Enable the option to edit Album Artists from cache list (Feature Request)

[abbluiz]

It seems the app already picks up Album Artists from supported players according with this issue: #120

However, I had no luck with Poweramp. It seems the app just gets the Artist and the Album Artists ends up with the same value.

But the real point here is to be able to at least edit the Album Artist from the scrobble cache before sending them... that way I won't need to edit them through Last.fm website every time I need to correct something.