Add Spotify teaser tracks for artists

[danielbogomazov]

When a user clicks on an upcoming recording's tableview cell, they should be able to listen to a teaser of the artist's top track.

Artist's top tracks:
https://developer.spotify.com/documentation/web-api/reference/artists/get-artists-top-tracks/

• /v1/artists/{id}/top-tracks

Track preview:
https://developer.spotify.com/documentation/web-api/reference/object-model/

• track object (full)
  • preview_url

Beta API reference: https://developer.spotify.com/documentation/web-api/reference-beta/

Provide a prompt when the user first opens the application for them to sign into their spotify account to provide apollo with the authentication token.
If they do not, grey out the music player and include a small notes prompting the user to login to have access to this feature.