feature: playlist support

[danielnbalasoiu]

Currently, only favorite (playlist) can be played.
It would be really useful to have multiple playlists to add items and play from.

[Bellisario]

Yes, this could be a great feature, but it could become very complex to make because:

• favorites saved will need to have some kind of menu to add them to a playlist
• saving (exporting/importing) favorites can become more complex and "space consuming" because every single music can have playlists where its saved (and we should save playlists, too).

There is a lot of work required to make this working and I don't think I'll implement very soon, but this is surely something to add...

[YAKSL]

i successfully imported playlists from YoutubeMusic (and Youtube) by exporting them as JSON and then slightly editing the file, for playlists from Spotify and other Music Platforms i used a Service that transforms/syncs playlists from-to different platforms and then exporting the transformed Youtube playlist as JSON.
Musicale successfully imported the playlists (JSON) to my favorites although the posters/artworks aren't present.