buymusic.club integration

[sabjorn]

• [ ] if item is purchasable:
  • [ ] add shopping cart icon next to each track
  • [ ] add shopping cart icon in player
• [ ] when cart icon is clicked, the item is added to user's cart in Bandcamp
• [ ] wishlist icon (heart) next to each track
• [ ] when wishlist icon is clicked, item is added to user's wishlist in Bandcamp

unknown: can wishlist icon persist? as in, when item clicked and added the state can change (filled in, like on Bandcamp) will this be possible to persist between loads? currently the problem will be that there is no query for singular wishlist items so the user's wishlist will need to be cached...