Pick a Spotify playlist for a preset key from a list

[JRpersonal]

Today a Spotify playlist gets onto a preset key by starting it in the Spotify app first and then holding the key. With this, the app's preset editor lists your Spotify playlists, Liked Songs included, and you pick one for the key directly, without playing it first. That also helps a second person in the household who wants to set a key.

It needs the Spotify engine update that brings the new library functions, and the list comes from the Spotify login of the speaker you are editing.

Vote with the upvote arrow if you want this; votes help me decide what comes next. Full backlog: #390