VideoPlayerViewController: Improve handling of external screen

This improves the overall experiences of external screens.

Still needs to be worked on:

• Minimize on external display
• When plugging the external screen while playing, the aspect ratio is off.

changed milestone to %3.3.0

added Interface Player labels

added 8 commits

• afde9bfb...5ea848a4 - 2 commits from branch videolan:master
• 2a926431 - VideoPlayerViewController: Simplify nullability check
• 24cb3172 - VideoPlayerViewController: Set default background color
• 97103f30 - VideoPlayerViewController: Set PlayerController delegate
• 3ece206c - VideoPlayerViewController: Remove nullability sanity check
• 16068724 - AudioMiniPlayer: change video output only without external screen
• d07a40cc - VideoPlayerViewController: Use PlayerController for userDefault

Compare with previous version

enabled an automatic merge when the pipeline for d07a40cc succeeds

merged