[Feature] Communications (#4)

This PR constains the work done to define the necessary protocols and enumerations to start defining remote API service as well as an implementation of the `URLProtocol` to mock requests and responses when using the `URLSession` to make remote calls.

To provide further details about this work:
- [x] declared the `Communications` library in the `Package` file;
- [x] defined the minimum Apple platform versions in the `Package` file to support the async/await feature;
- [x] defined the `HTTPRequestMethod` and `HTTPResponseCode` public enumerations;
- [x] defined the `Endpoint` and `Client` public protocols;
- [x] implemented the internal `MakeURLRequestUseCase` use case;
- [x] implemented the `MockURLProtocol` class that mocks requests and responses on `URLSession` instances;
- [x] started writing and updating the `README` file.

Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Reviewed-on: #4

Sources/Communications/Protocols/Client.swift

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+//
+//  Client.swift
+//  Communications
+//
+//  Created by Javier Cicchelli on 10/04/2023.
+//  Copyright © 2023 Röck+Cöde. All rights reserved.
+//
+
+import Foundation
+
+/// This protocol defines a client that will be making the remote calls.
+public protocol Client {
+    
+    // MARK: Functions
+
+    /// Makes a request to a remote location based on a given endpoint and expects to return a response casted as a given model type.
+    /// - Parameters:
+    ///   - endpoint: The endpoint for which to make a remote call.
+    ///   - model: The model to cast an expected response from the remote location.
+    /// - Returns: A casted model instance created out of a response retrieved from a call to a remote endpoint.
+    func request<Model: Decodable>(
+        endpoint: some Endpoint,
+        as model: Model.Type
+    ) async throws -> Model
+    
+    /// Makes a request to a remote location based on a given endpoint and expects to return an original, uncasted response.
+    /// - Parameter endpoint: The endpoint for which to make a remote call.
+    /// - Returns: An original data response from a call to a remote endpoint.
+    @discardableResult func request(endpoint: some Endpoint) async throws -> Data
+
+}

Sources/Communications/Protocols/Endpoint.swift

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+//
+//  Endpoint.swift
+//  Communications
+//
+//  Created by Javier Cicchelli on 10/04/2023.
+//  Copyright © 2023 Röck+Cöde. All rights reserved.
+//
+
+import Foundation
+
+/// This protocol defines an endpoint to be used in a remote call.
+public protocol Endpoint {
+    
+    // MARK: Properties
+
+    /// The scheme subcomponent for the endpoint.
+    var scheme: String { get }
+    
+    /// The host subcomponent for the endpoint.
+    var host: String { get }
+
+    /// The port subcomponent for the component.
+    var port: Int? { get }
+
+    /// The path subcomponent for the endpoint.
+    var path: String { get }
+    
+    /// The HTTP request method for the endpoint.
+    var method: HTTPRequestMethod { get }
+    
+    /// The HTTP header fields as a dictionary for the endpoint.
+    var headers: [String: String] { get }
+    
+    /// The message body as data for a request.
+    var body: Data? { get }
+
+}