Replace ResourceMixin/accessible_objects/accessible_pk_qs with DAB RBAC access_qs/access_ids_qs
Remove the ResourceMixin class and migrate all callers to the new
DAB RBAC queryset API: access_qs replaces accessible_objects and
access_ids_qs replaces accessible_pk_qs, using permission strings
(view, change, use, etc.) instead of role field names.
Also updates prefetch_page_capabilities to use permission-based
capability definitions instead of role field references.
Restore UNION pattern in TeamAccess.filtered_queryset
The access_qs migration accidentally collapsed the UNION into an OR,
which can be 48x slower at scale (AAP-83319).
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>