Add a way to shuffle all songs

[0d-billie]

Is your feature request related to a problem? Please describe.
When I used to maintain a winamp/iTunes library, one of my favourite things was being able to shuffle my entire library. It would be really nice to have an option to do the same here! A simple button to "shuffle all" would be grand, or at least a view of my library in the older fashion of having the full thing in one list.

Describe alternatives you've considered
Symfonium has a "song mix" option which generates a playlist of 200 random songs (at least I think they're random, it might weight towards songs which are adjacent to already "liked" ones). If being able to shuffle the entire library is not possible for whatever reason (presumably due to limitations on the server side?) then this might be a good alternative.

Additional context
I only have one single source: a remotely available navidrome instance. So when I say library, I am referring only to what is being served by this one source. Without knowing much about the inner workings of this application or the subsonic protocol, I don't know if this would struggle with multiple sources.

[NattyNarwhal]

Should be a matter of exposing getRandomSongs basically