AudioPlayer: New Audio Player interface

This merge request brings:

• The addition of a class implementing all the generic features a player could possibly have, for abstraction purposes and avoid duplicate code.
• The addition of a group in the project architecture called "Player", grouping all the files related to the players implementations.
• The addition of an audio player view controller based on the generic class introduced beforehand.
• The addition of a new audio player view, introducing an improved user experience.
• The addition of an UIImage extension allowing us to retrieve the average color of an image.

This audio player view also introduces a new layout for:

• The playqueue, that is now integrated in a more consistent way regarding the iOS environment.
• The player controls, displaying also the useful controls for audio playback.
• The audio options, removing the unnecessary options (like the video filters for example).
• The background color that is set accordingly to the average color of the media's thumbnail.

The introduction of the new audio player is only effective for devices running with iOS 13.0 and above, in order to avoid overloading older devices.

New audio player screenshots

Closes #1276 (closed)

Closes #1277 (closed)