Force/select alternative source for metadata (cover art, artist art, etc.)

Suggest adding an ability to override metadata from an online source (like Subsonic/Navidrome server) with metadata fetched from an alternative source by the app directly (e.g. Substreamer fetches the artist images from if I am not mistaken).

Also here:

  • Ability to manually add a cover for an album and/or artist
  • Ability to fetch album cover as well as artist arts (although imo artist is a priority)
  • Ability to select metadata source

Out of scope sorry, Symfonium relies on the provider to provide the data, having a server but different data on each client app does not make sense, the data should be updated on the server so that everyone have the data you want.