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/core/migrations/0008_contenttype_proxy.py

@@ -1,4 +1,4 @@
-import core.models.contenttypes
+import core.models.object_types
 from django.db import migrations
 
 
@@ -19,7 +19,7 @@ class Migration(migrations.Migration):
             },
             bases=('contenttypes.contenttype',),
             managers=[
-                ('objects', core.models.contenttypes.ObjectTypeManager()),
+                ('objects', core.models.object_types.ObjectTypeManager()),
             ],
         ),
     ]

netbox/core/migrations/0018_concrete_objecttype.py

@@ -0,0 +1,63 @@
+import django.contrib.postgres.fields
+import django.contrib.postgres.indexes
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+        ('core', '0017_objectchange_message'),
+    ]
+
+    operations = [
+        # Delete the proxy model from the migration state
+        migrations.DeleteModel(
+            name='ObjectType',
+        ),
+        # Create the new concrete model
+        migrations.CreateModel(
+            name='ObjectType',
+            fields=[
+                (
+                    'contenttype_ptr',
+                    models.OneToOneField(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        parent_link=True,
+                        primary_key=True,
+                        serialize=False,
+                        to='contenttypes.contenttype',
+                        related_name='object_type'
+                    )
+                ),
+                (
+                    'public',
+                    models.BooleanField(
+                        default=False
+                    )
+                ),
+                (
+                    'features',
+                    django.contrib.postgres.fields.ArrayField(
+                        base_field=models.CharField(max_length=50),
+                        default=list,
+                        size=None
+                    )
+                ),
+            ],
+            options={
+                'verbose_name': 'object type',
+                'verbose_name_plural': 'object types',
+                'ordering': ('app_label', 'model'),
+                'indexes': [
+                    django.contrib.postgres.indexes.GinIndex(
+                        fields=['features'],
+                        name='core_object_feature_aec4de_gin'
+                    ),
+                ]
+            },
+            bases=('contenttypes.contenttype',),
+            managers=[],
+        ),
+    ]