Add "Favorites" to Logitech Squeezebox

Tags: #<Tag:0x00007fc3f0439de0>

The Logitech Media Server has a “Favorites” option, but it’s not accessible from HA.
It would be nice to have it available in the integration, and from Lovelace, so we can choose the music source from the list of favorites.

Merge with Support for Squeezebox Favorites