Release 5.12.0

• Merge pull request #243 from internet4000/fix/track-availability (c78f07a)
• Fix old YouTube ID for availability check (cbca703)
• Merge pull request #241 from internet4000/feat/track-dead-link (be32b86)
• feat: only display dead media links to channel owner (5fb1063)
• fix: youtube-api adapter, fetchTrack returned wrong value (b591b68)
• Upgrade radio4000-player for latest build (7c912b3)
• Merge branch 'feat/track-dead-link' of github.com:internet4000/radio4000 into feat/track-dead-link (120dae7)
• chore: bump radio4000-player to 0.5.1 for get new event (0c882a5)
• Update copy in track edit form (b50023d)
• Fix youtube api guard (d710cb1)
• Lint (baaf053)
• Fix fetch title for bad URLs (7606b26)
• fix: put back npm player (instead of local) (e33f36a)
• feat: only set track as unavailable for track owner (03928d1)
• feat: track can be put out of no media avialable mode (956f4f1)
• feat: add possibility to mark the track media as available (e730d2a)
• feat: check track youtube media availability on update (64fe29b)
• feat: refactor youtube fetchTitle for track model (f0e46f1)
• feat: add notification on track when its media is not available (da696c9)