macosx: update play and playback mode status on startup

Because the playback might have been started before the interface
registeres its callbacks, set the state manually.

close #14046

(cherry picked from commit 5598f816905d5262928650c38d6b9a501b232deb)
Signed-off-by: David Fuhrmann <dfuhrmann@videolan.org>

modules/gui/macosx/intf.m

@@ -797,6 +797,13 @@ static VLCMain *_o_sharedMainInstance = nil;
     [o_mainwindow updateTimeSlider];
     [o_mainwindow updateVolumeSlider];
 
+    /* Hack: Playlist is started before the interface.
+     * Thus, call additional updaters as we might miss these events if posted before
+     * the callbacks are registered.
+     */
+    [self PlaylistItemChanged];
+    [self playbackModeUpdated];
+
     // respect playlist-autostart
     // note that PLAYLIST_PLAY will not stop any playback if already started
     playlist_t * p_playlist = pl_Get(VLCIntf);