Made all TrackLink properties nil. will never fail to decode TrackL…

…ink again.

Sources/SpotifyWebAPI/Object Model/Other Spotify Objects/TrackLink.swift

@@ -5,8 +5,8 @@ import Foundation
 ///
 /// See the [Track relinking Guide][2].
 /// [2]: https://developer.spotify.com/documentation/general/guides/track-relinking-guide/
-public struct TrackLink: SpotifyURIConvertible, Hashable {
-    
+public struct TrackLink: Hashable {
+
     /**
      Known external urls for this track.
 
@@ -23,21 +23,21 @@ public struct TrackLink: SpotifyURIConvertible, Hashable {
      
      Use ``SpotifyAPI/getFromHref(_:responseType:)`` to retrieve the results.
      */
-    public let href: URL
-    
+    public let href: URL?
+
     /// The [Spotify URI][1] for the track.
     ///
     /// [1]: https://developer.spotify.com/documentation/web-api/#spotify-uris-and-ids
-    public let uri: String
-    
+    public let uri: String?
+
     /// The [Spotify ID][1] for the track.
     ///
     /// [1]: https://developer.spotify.com/documentation/web-api/#spotify-uris-and-ids
-    public let id: String
-    
+    public let id: String?
+
     /// The object type. Always ``IDCategory/track``.
     public let type: IDCategory
-    
+
     /**
      Creates a Spotify track link object.
      
@@ -73,6 +73,30 @@ public struct TrackLink: SpotifyURIConvertible, Hashable {
 
 extension TrackLink: Codable {
 
+    public init(from decoder: any Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+
+        self.externalURLs = try? container.decodeIfPresent(
+            [String : URL].self, forKey: .externalURLs
+        )
+
+        self.href = try? container.decodeIfPresent(
+            URL.self, forKey: .href
+        )
+
+        self.uri = try? container.decodeIfPresent(
+            String.self, forKey: .uri
+        )
+
+        self.id = try? container.decodeIfPresent(
+            String.self, forKey: .id
+        )
+
+        self.type = (try? container.decodeIfPresent(
+            IDCategory.self, forKey: .type
+        )) ?? .track
+    }
+
     private enum CodingKeys: String, CodingKey {
         case externalURLs = "external_urls"
         case href