Allow matching primary groups on arbitrary field

Add setting which field from group model should be used to match against.

changed milestone to %2.0a2

assigned to @nik

changed title from Improve RegEx match of primary groups to Allow matching primary groups on arbitrary field

created merge request !248 (merged) to address this issue

mentioned in merge request !248 (merged)

mentioned in commit 95bb9aa0

closed via merge request !248 (merged)

added part::backend prio::1 type::feature workflow::confirmed labels