Give preference to pinned or commonly used playlists when adding songs.

[ConalM]

Desktop App: When I add new songs to existing playlists, I should be able to access my most used lists or the ones I have pinned to the top of my library. This used to be the case, but now it seems to be done alphabetically. There is an option to find the playlist, but that's an unnecessary step. I think most people will find it useful to have any pinned playlist easily accessible.