mpd: Test that "list album foo" responds correctly

Previously, test_list_album_with_artist_name would only test that the
command didn't fail. Now it also checks that the response is correct.
That is, that the response contains albums.

This makes the test detect the error reported in #817.

(cherry picked from commit 9771eda23068f4581a30059ac597f1360d349dcd)
mpd: Fix list commands with 3 arguments (fixes #817)

List commands with 3 arguments should return albums, not artists.

(cherry picked from commit ec413126f1670ccf4f5853e6ee375239cdb374e6)
docs: Add the mpd list command fix to the changelog

(cherry picked from commit 92fa75325d968bb271b8601447080c29bccbde5f)

Conflicts:
	docs/changelog.rst
docs: Fix formatting

(cherry picked from commit 26cfd24e113801b23a00bfb5d6706ee66e643e5b)