AAP-51957 Move to new DAB RBAC queryset patterns (#16118)

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>

docs/docsite/rst/contributor/DJANGO_REQUIREMENTS.rst

@@ -219,11 +219,6 @@ This example allows the Django debug toolbar to work.
 .. code-block:: python
 
     # models/mixins.py
-    class ResourceMixin(models.Model):
-        """Common resource management functionality"""
-        class Meta:
-            abstract = True
-
     class ExecutionEnvironmentMixin(models.Model):
         """Execution environment configuration"""
         class Meta: