Closes #12246: General cleanup of utilities modules

* Clean up base modules

* Clean up forms modules

* Clean up templatetags modules

* Replace custom simplify_decimal filter with floatformat

* Misc cleanup

* Merge ReturnURLForm into ConfirmationForm

* Clean up import statements for utilities.forms

* Fix field class references in docs

netbox/utilities/querysets.py

@@ -3,6 +3,11 @@ from django.db.models import Prefetch, QuerySet
 from users.constants import CONSTRAINT_TOKEN_USER
 from utilities.permissions import permission_is_exempt, qs_filter_from_constraints
 
+__all__ = (
+    'RestrictedPrefetch',
+    'RestrictedQuerySet',
+)
+
 
 class RestrictedPrefetch(Prefetch):
     """