Added new messages for returning users with playlists.

messageTypes.ts

@@ -23,6 +23,7 @@ export type StuenMessages =
     | Playlists
     | GetPlaylist
     | PlaylistSongs
+    | GetListenersWithPlaylists
     | ToggleTag
     | Shuffle
     | RemoveFromAutoPlay
@@ -153,12 +154,19 @@ export class GetPlaylist extends StuenMessage {
         super('GetPlaylist');
     }
 }
+
 export class PlaylistSongs extends StuenMessage {
     constructor(public playlist: Playlist) {
         super('PlaylistSongs');
     }
 }
 
+export class GetListenersWithPlaylists extends StuenMessage {
+    constructor() {
+        super('GetListenersWithPlaylists');
+    }
+}
+
 export class AddSongToPlaylist extends StuenMessage {
     constructor(public song: Song, public playlist: string) {
         super('AddSongToPlaylist');