Force lookup for newly added albums/artists

Feature description:

It would be good to be able to force a refresh even manually, to look up newly added albums.

Problem solved:

Currently it looks like new albums are looked up/synced whenever the application is launched, I presume? However, it would be good to also be able to manually “refresh” induce this lookup of new items. Sometimes, it is not exactly clear when Symfonium looks for the newly added albums to recognize, because sometimes new albums do not show up in Symfonium even after multiple relaunches, even though new files have been added to the connected Subsonic server.

Brought benefits:

Whenever a refresh does not happen automatically, it should be possible for the user to “induce” such a database refresh/rescan.