fix(kavita): move libraries to /var/lib/libraries
Previously we had our libraries in a subdirectory of /var/lib/copyparty
While that's an OK idea in theory, in practice it'd require us to make
every directory on the way to /var/lib/copyparty/data/groups/library
+rx to kavita. That's something we're unwilling to do. The true fix is
to move this out so we don't have to meddle with permissions except
those which are directly on this directory