Implemented the Authentication middleware (#3)

This PR contains the work done to implement the `AuthMiddleware` middleware, to authenticate the requests sent to the backend service, based on [their specifications](https://www.discogs.com/developers/#page:authentication).

In addition, some documentation has been added/updated and some boilerplate source code has been removed from the project.

Reviewed-on: #3
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

docs/data/documentation/discogsservice/components/schemas/release/codingkeys/notes.json

@@ -1 +1 @@
-{"hierarchy":{"paths":[["doc:\/\/DiscogsService\/documentation\/DiscogsService","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys"]]},"identifier":{"interfaceLanguage":"swift","url":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys\/notes"},"variants":[{"paths":["\/documentation\/discogsservice\/components\/schemas\/release\/codingkeys\/notes"],"traits":[{"interfaceLanguage":"swift"}]}],"kind":"symbol","schemaVersion":{"major":0,"minor":3,"patch":0},"primaryContentSections":[{"declarations":[{"platforms":["macOS"],"tokens":[{"text":"case","kind":"keyword"},{"text":" ","kind":"text"},{"text":"notes","kind":"identifier"}],"languages":["swift"]}],"kind":"declarations"}],"sections":[],"metadata":{"title":"Components.Schemas.Release.CodingKeys.notes","fragments":[{"text":"case","kind":"keyword"},{"text":" ","kind":"text"},{"text":"notes","kind":"identifier"}],"modules":[{"name":"DiscogsService"}],"externalID":"s:14DiscogsService10ComponentsO7SchemasO7ReleaseV10CodingKeysO5notesyA2ImF","symbolKind":"case","role":"symbol","roleHeading":"Case"},"references":{"doc://DiscogsService/documentation/DiscogsService/Components/Schemas":{"identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas","type":"topic","url":"\/documentation\/discogsservice\/components\/schemas","abstract":[{"type":"text","text":"Types generated from the "},{"code":"#\/components\/schemas","type":"codeVoice"},{"type":"text","text":" section of the OpenAPI document."}],"role":"symbol","kind":"symbol","navigatorTitle":[{"text":"Schemas","kind":"identifier"}],"title":"Components.Schemas","fragments":[{"text":"enum","kind":"keyword"},{"text":" ","kind":"text"},{"text":"Schemas","kind":"identifier"}]},"doc://DiscogsService/documentation/DiscogsService/Components":{"type":"topic","url":"\/documentation\/discogsservice\/components","role":"symbol","identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components","kind":"symbol","title":"Components","navigatorTitle":[{"text":"Components","kind":"identifier"}],"abstract":[{"text":"Types generated from the components section of the OpenAPI document.","type":"text"}],"fragments":[{"kind":"keyword","text":"enum"},{"text":" ","kind":"text"},{"kind":"identifier","text":"Components"}]},"doc://DiscogsService/documentation/DiscogsService/Components/Schemas/Release/CodingKeys/notes":{"fragments":[{"text":"case","kind":"keyword"},{"text":" ","kind":"text"},{"text":"notes","kind":"identifier"}],"url":"\/documentation\/discogsservice\/components\/schemas\/release\/codingkeys\/notes","role":"symbol","type":"topic","kind":"symbol","identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys\/notes","abstract":[],"title":"Components.Schemas.Release.CodingKeys.notes"},"doc://DiscogsService/documentation/DiscogsService/Components/Schemas/Release/CodingKeys":{"identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys","type":"topic","url":"\/documentation\/discogsservice\/components\/schemas\/release\/codingkeys","abstract":[],"role":"symbol","kind":"symbol","navigatorTitle":[{"text":"CodingKeys","kind":"identifier"}],"title":"Components.Schemas.Release.CodingKeys","fragments":[{"text":"enum","kind":"keyword"},{"text":" ","kind":"text"},{"text":"CodingKeys","kind":"identifier"}]},"doc://DiscogsService/documentation/DiscogsService/Components/Schemas/Release":{"identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release","type":"topic","url":"\/documentation\/discogsservice\/components\/schemas\/release","abstract":[{"type":"text","text":"A type that eepresents a particular physical or digital object released by one or more artists."}],"role":"symbol","kind":"symbol","navigatorTitle":[{"text":"Release","kind":"identifier"}],"title":"Components.Schemas.Release","fragments":[{"text":"struct","kind":"keyword"},{"text":" ","kind":"text"},{"text":"Release","kind":"identifier"}]},"doc://DiscogsService/documentation/DiscogsService":{"url":"\/documentation\/discogsservice","abstract":[],"identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService","kind":"symbol","role":"collection","type":"topic","title":"DiscogsService"}}}
+{"kind":"symbol","hierarchy":{"paths":[["doc:\/\/DiscogsService\/documentation\/DiscogsService","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release","doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys"]]},"variants":[{"traits":[{"interfaceLanguage":"swift"}],"paths":["\/documentation\/discogsservice\/components\/schemas\/release\/codingkeys\/notes"]}],"primaryContentSections":[{"kind":"declarations","declarations":[{"tokens":[{"text":"case","kind":"keyword"},{"text":" ","kind":"text"},{"text":"notes","kind":"identifier"}],"platforms":["macOS"],"languages":["swift"]}]}],"identifier":{"interfaceLanguage":"swift","url":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys\/notes"},"schemaVersion":{"minor":3,"major":0,"patch":0},"metadata":{"role":"symbol","symbolKind":"case","title":"Components.Schemas.Release.CodingKeys.notes","fragments":[{"kind":"keyword","text":"case"},{"kind":"text","text":" "},{"kind":"identifier","text":"notes"}],"externalID":"s:14DiscogsService10ComponentsO7SchemasO7ReleaseV10CodingKeysO5notesyA2ImF","roleHeading":"Case","modules":[{"name":"DiscogsService"}]},"sections":[],"references":{"doc://DiscogsService/documentation/DiscogsService":{"role":"collection","title":"DiscogsService","kind":"symbol","identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService","abstract":[],"type":"topic","url":"\/documentation\/discogsservice"},"doc://DiscogsService/documentation/DiscogsService/Components/Schemas/Release/CodingKeys/notes":{"kind":"symbol","role":"symbol","url":"\/documentation\/discogsservice\/components\/schemas\/release\/codingkeys\/notes","title":"Components.Schemas.Release.CodingKeys.notes","fragments":[{"text":"case","kind":"keyword"},{"text":" ","kind":"text"},{"text":"notes","kind":"identifier"}],"abstract":[],"identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys\/notes","type":"topic"},"doc://DiscogsService/documentation/DiscogsService/Components/Schemas/Release":{"fragments":[{"text":"struct","kind":"keyword"},{"kind":"text","text":" "},{"kind":"identifier","text":"Release"}],"role":"symbol","navigatorTitle":[{"text":"Release","kind":"identifier"}],"title":"Components.Schemas.Release","kind":"symbol","identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release","abstract":[{"type":"text","text":"A type that eepresents a particular physical or digital object released by one or more artists."}],"type":"topic","url":"\/documentation\/discogsservice\/components\/schemas\/release"},"doc://DiscogsService/documentation/DiscogsService/Components/Schemas":{"role":"symbol","type":"topic","abstract":[{"type":"text","text":"Types generated from the "},{"code":"#\/components\/schemas","type":"codeVoice"},{"text":" section of the OpenAPI document.","type":"text"}],"kind":"symbol","identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas","url":"\/documentation\/discogsservice\/components\/schemas","navigatorTitle":[{"text":"Schemas","kind":"identifier"}],"title":"Components.Schemas","fragments":[{"text":"enum","kind":"keyword"},{"text":" ","kind":"text"},{"text":"Schemas","kind":"identifier"}]},"doc://DiscogsService/documentation/DiscogsService/Components/Schemas/Release/CodingKeys":{"fragments":[{"text":"enum","kind":"keyword"},{"text":" ","kind":"text"},{"text":"CodingKeys","kind":"identifier"}],"role":"symbol","navigatorTitle":[{"text":"CodingKeys","kind":"identifier"}],"title":"Components.Schemas.Release.CodingKeys","kind":"symbol","identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components\/Schemas\/Release\/CodingKeys","abstract":[],"type":"topic","url":"\/documentation\/discogsservice\/components\/schemas\/release\/codingkeys"},"doc://DiscogsService/documentation/DiscogsService/Components":{"title":"Components","identifier":"doc:\/\/DiscogsService\/documentation\/DiscogsService\/Components","navigatorTitle":[{"text":"Components","kind":"identifier"}],"abstract":[{"type":"text","text":"Types generated from the components section of the OpenAPI document."}],"type":"topic","fragments":[{"text":"enum","kind":"keyword"},{"text":" ","kind":"text"},{"text":"Components","kind":"identifier"}],"role":"symbol","url":"\/documentation\/discogsservice\/components","kind":"symbol"}}}