discogs: add support for extra_tags #6261
Description
Implement a similar system to the extra_tags option in the musicbrainz plugin to allow the Discogs
plugin to better find the correct release if given more information.
The current search system does not use Discogs's advanced search options at all, and only searches with a general string of artist and album if it does not think it is a VA release, and just use the album title otherwise.