Closes #19924: Record model features on ObjectType (#19939)

* Convert ObjectType to a concrete child model of ContentType

* Add public flag to ObjectType

* Catch post_migrate signal to update ObjectTypes

* Reference ObjectType records instead of registry for feature support

* Automatically create ObjectTypes

* Introduce has_feature() utility function

* ObjectTypeManager should not inherit from ContentTypeManager

* Misc cleanup

* Don't populate ObjectTypes during migration

* Don't automatically create ObjectTypes when a ContentType is created

* Fix test

* Extend has_feature() to accept a model or OT/CT

* Misc cleanup

* Deprecate get_for_id() on ObjectTypeManager

* Rename contenttypes.py to object_types.py

* Add index to features ArrayField

* Keep FK & M2M fields pointing to ContentType

* Add get_for_models() to ObjectTypeManager

* Add tests for manager methods & utility functions

* Fix migrations for M2M relations to ObjectType

* model_is_public() should return False for non-core & non-plugin models

* Order ObjectType by app_label & model name

* Resolve migrations conflict

netbox/dcim/models/cables.py

@@ -1,6 +1,7 @@
 import itertools
 
 from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.dispatch import Signal
@@ -479,13 +480,13 @@ class CablePath(models.Model):
     def origin_type(self):
         if self.path:
             ct_id, _ = decompile_path_node(self.path[0][0])
-            return ObjectType.objects.get_for_id(ct_id)
+            return ContentType.objects.get_for_id(ct_id)
 
     @property
     def destination_type(self):
         if self.is_complete:
             ct_id, _ = decompile_path_node(self.path[-1][0])
-            return ObjectType.objects.get_for_id(ct_id)
+            return ContentType.objects.get_for_id(ct_id)
 
     @property
     def _path_decompiled(self):