Feat/genres-v2-implementation (#3164)

* feat(genres): Core genre system

* feat(genres): add background scanner for metadata.genres

* refactor(genres): add genres to base

* test(genres): add test suite

* fix(genres): eixsting genres are not recreated at migration

* feat(genres): guard against infinite loops in scanner

* fix(genres): remove duplicate, improve tests

* fix(genres): limit genre tracks return

* refactor(genres): use logger rather than print

* refactor(genres): use asyncio.gather rather than sequential calls

* refactor(genres): various fixes after review comments

* refactor(genres): randomize selection, use asyncio gether

* refactor(genres): remove alias object

* fix(genres): fix n:n relationship, safeguard comparisons

* refactor(genres): address review comments

* fix(genres): fix issues after rebase

* test(genres): add missing param to library sync tests