stream-composer: cache and sync now-playing

[pyldin601]

When radio channel is playing, it should cache somewhere actual now-playing title and sync it with database if needed. This will solve syncing issues when stream-composer will start playing next track always from the beginning of the track.

Subtasks:

• Add caching service to myownradio services
• Save now playing into cache when radio channel is playing
• Sync difference if current track's timing differs from scheduled
• Play next track from the beginning with fixing time difference

[tarsisexistence]

@pldin601 this was created almost 1 year ago.

do you plan to have some progress on this?