Add a play queue to the player

There should be a Play queue available that would always be played before any additional media.

It should be possible to add any available media (albums, videos, albums, TV seasons, even the whole series) to the play queue using a contextual action. There should be two available actions - append to queue or add after currently played media.

Whenever the play queue would be active, the default action for media should be changed from 'play' to 'queue' so that the media should not be interrupted unless from the player.

It's needed to be possible to remove, re-order individual entries or purge the play queue completely.