[ifcbrk] feature: Implement Client Status Support (#1247)

* Implement Client Status Support

Adds support for using the client_status as sent as part of the Presence model. This value can be used to determine if a user is active on the native desktop app, the mobile app, or the website.

* lint: whitespace in IPresence

* Remove breaking change to IPresence interface with a note for 2.1

* update comment to not reference 2.1

* re-add interface break to IPresence

* add example payload for client_status

* use inline declaration for Enum.TryParse

src/Discord.Net.WebSocket/Entities/Users/SocketUnknownUser.cs

@@ -24,8 +24,8 @@ namespace Discord.WebSocket
         
         /// <inheritdoc />
         public override bool IsWebhook => false;
-
-        internal override SocketPresence Presence { get { return new SocketPresence(UserStatus.Offline, null); } set { } }
+        /// <inheritdoc />
+        internal override SocketPresence Presence { get { return new SocketPresence(UserStatus.Offline, null, null); } set { } }
         /// <inheritdoc />
         /// <exception cref="NotSupportedException">This field is not supported for an unknown user.</exception>
         internal override SocketGlobalUser GlobalUser =>