Add base shortcuts

[max246]

This is part of the request #1645 , it adds shortcuts to the UI

Adding the media control for:
Mute
Volume Up/Down
Play/Pause
Stop
Prev/Next track

Unfortunately you need to have the window focus to make it work since mediaSession doesnt seems to work with my integration

[marcelveldt]

see in-line feedback - keep the PR small and simple and focus only on the media controls. Also, you are only accounting for the happy flow now. If the api connection is not there yet or no player is active this will crash

[marcelveldt]

I've just tested this PR and it was not working, especially not in the subpages.
So back to the drawing board, we might want to look into mediaSession again