Enhance music player

[postcanonical]

It is better to have a music player that can play music in background. That way user can listen to audio and scroll chats at the same time.

Maybe add some type of simple queue control.

Another way I see it, we can have a toggle in settings to open every audio file in separate app. Element can even generate some playlists for it to play (e.g. m3u) based on the room or thread (when threads will be implemented).