Apollo: update Last.fm api

Update ImageSize class.

Artist.getImages is deprecated now. Remove it
and use Artist.getInfo to load images for Artist.

Use default album size to EXTRALARGE.
Add a function to check album size and fallback to smaller
one if does not exists,

Change-Id: I40e3d5c60397a620057619dca1a7ea3e5839c7de