VLCPlayerDisplayController: Add key commands for the mini player
This merge request adds key commands for the mini player.
The users can now control the mini player with an external keyboard while navigating through the application.
Just like the other players, the users can now use the following commands:
- Play / pause the playback
- Seek backwards / forwards
- Increase / decrease / reset the playback rate
Closes #1357 (closed)