Add owner_qs to replace owner_qs_for_cluster

refs #14367
Change imports to owner_qs

refs #14367
Sort owner_qs and owner_qs_for_superuser by name

refs #14367
Separate out filtering groups into its own function

Add doc strings to new backend queries.

Change filtering to use intersection rather than looping through queryset.

refs #14367
Allow changing password with create_user

refs #14367
Fix repr in ClusterUser.

Now Profiles and Organizations repr's are consistent with their real_type being
printed, rather than the ClusterUser type.

refs #14367
Test cluster_qs with users (no groups)

refs #14367
Test owner_qs with users in groups.

refs #14367