Adjustments to the Localization package dependency (#11)

This PR contains the work done to refactor the _Localization_ package and tidy the project a little bit.

To provider further details about the work:

* The `Negotiate` function was moved to the _Localization_ package.
* The `WebsiteRequestContext` context no longer resolves a default language at creation; it starts empty and relies on the `LocalizationMiddleware` middleware to fill it in.
* Fixed the local dependency path to Packages/Localization for the **Website** package as it only resolved inside the Xcode workspace before, breaking swift build, the Makefile, and the Docker build).
* Updated the `README` file to document language negotiation, the GET /health route, and the full middleware chain; doc comments across the moved/renamed types were brought back in sync with the code.

Reviewed-on: rock-n-code/loud-amsterdam#11
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>

Services/Website/.swiftpm/xcode/xcshareddata/xcschemes/Website.xcscheme

@@ -26,13 +26,8 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "YES">
-      <TestPlans>
-         <TestPlanReference
-            reference = "container:Website.xctestplan"
-            default = "YES">
-         </TestPlanReference>
-      </TestPlans>
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
       <Testables>
          <TestableReference
             skipped = "NO">
@@ -50,8 +45,7 @@
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       launchStyle = "0"
-      useCustomWorkingDirectory = "YES"
-      customWorkingDirectory = "/Users/logan/Documents/Development/Platforms/Ro&#x308;ck+Co&#x308;de/Loud/Services/Website"
+      useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
       debugServiceExtension = "internal"