feat: approve users, edit users through manage users page (#1383)

cms/auth_backends.py

@@ -0,0 +1,10 @@
+from django.conf import settings
+from django.contrib.auth.backends import ModelBackend
+
+
+class ApprovalBackend(ModelBackend):
+    def user_can_authenticate(self, user):
+        can_authenticate = super().user_can_authenticate(user)
+        if can_authenticate and settings.USERS_NEEDS_TO_BE_APPROVED and not user.is_superuser:
+            return getattr(user, 'is_approved', False)
+        return can_authenticate