360° support in SRGMediaPlayerViewController

[defagos]

Now that SRGMediaPlayerViewController is implemented with AVPlayerViewController, we must in general use the associated AVPlayerLayer and not attempt to replace it with our own instantiated with SRGMediaPlayerView. If we do, we lose native features like PiP, AirPlay or volume controls.

For 360° playback, though, PiP and AirPlay do not make sense. We could attempt to:

• Swap the view with our own for 360° playback only.
• Find a way to disable these features in this case.
• Disable volume controls as well.
• Add a gesture recognizer to let the user move in 3D-space.

This is of course quite experimental and not required, but could still be interesting to provide a view controller able to play all kinds of contents.