fix: Remove obsolete methods and properties (#1849)

* Remove obsolete methods and properties

* Remove rest of GuildEmbed

* Remove TokenType.User

* Changes regarding the removal of the user tokentype

src/Discord.Net.WebSocket/Entities/Invites/SocketInvite.cs

@@ -49,9 +49,6 @@ namespace Discord.WebSocket
         /// <inheritdoc />
         int? IInvite.MemberCount => throw new NotImplementedException();
         /// <inheritdoc />
-        [Obsolete("This property doesn't exist anymore and shouldn't be used.")]
-        bool IInviteMetadata.IsRevoked => throw new NotImplementedException();
-        /// <inheritdoc />
         public bool IsTemporary { get; private set; }
         /// <inheritdoc />
         int? IInviteMetadata.MaxAge { get => MaxAge; }