[gnome-music] (6 commits) Non-fast-forward update to branch wip/jfelder/player-core-small-cleanups

[Jean Felder <jfelder src gnome org>]

The branch 'wip/jfelder/player-core-small-cleanups' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  80f64a6... player: Remove playerfield
  e0a800a... player: Stop the player if the playlist becomes empty
  625aa41... playertoolbar: Hide the toolbar if the playlist becomes emp

Commits added to the branch:

  5cd3c0e... grltrackerplaylists: Correctly add songs to user playlists (*)
  f0982b8... css: Prevent the text from being invisible on row selection (*)
  6f5b762... meson: Relax appdata file validation (*)
  1b3ee39... player: Remove playerfield
  19b6b4a... player: Stop the player if the playlist becomes empty
  21b48b3... playertoolbar: Hide the toolbar if the playlist becomes emp

(*) This commit already existed in another branch; no separate mail sent