Handle Subsonic multiple media folders as different libraries for filtering

Issue description:

I am sorry for asking as this is (probably?) a basic functionality, but I fail to find it in the app and I failed at searching for it:
How can I switch “media folders” in the app? The app seems to merge all albums from all media folders.
In the Airsonic server (same for Subsonic), I have configured different media folders to scan: Like one for music, one for audiobooks, one for bad music I usually don’t listen anymore.

In DSub you then select either “All” or one specific folder to show.

This is not possible for now as when I checked most maintained servers did not implemented this so I did not bother.

And your server despite maintained never reacted to be more compatible with Symfonium or OpenSubsonic.

If you can send me an access to your server in private with those multiple source I can look into adding that.

Ohh ok, I see. Yeah great, would be awesome if you could make it possible. I will be happy to send you credentials, thanks!

You are surely way better aware than I am but these are the folders I am talking about:

Well, regarding the maintenance of Airsonic - what I can I say? I understand your frustration. I still have hopes that Kagemomiji will be able to work on the API upgrades.