Closes #13427: Public model registration (#14152)

* Initial work on #13427

* Clarify documentation

* Reference public models registry when populating models for ConfigTemplate context

netbox/extras/dashboard/widgets.py

@@ -7,15 +7,13 @@ import feedparser
 import requests
 from django import forms
 from django.conf import settings
-from django.contrib.contenttypes.models import ContentType
 from django.core.cache import cache
-from django.db.models import Q
 from django.template.loader import render_to_string
 from django.urls import NoReverseMatch, resolve, reverse
 from django.utils.translation import gettext as _
 
+from core.models import ContentType
 from extras.choices import BookmarkOrderingChoices
-from extras.utils import FeatureQuery
 from utilities.choices import ButtonColorChoices
 from utilities.forms import BootstrapMixin
 from utilities.permissions import get_permission_for_model
@@ -37,10 +35,7 @@ __all__ = (
 def get_content_type_labels():
     return [
         (content_type_identifier(ct), content_type_name(ct))
-        for ct in ContentType.objects.filter(
-            FeatureQuery('export_templates').get_query() | Q(app_label='extras', model='objectchange') |
-            Q(app_label='extras', model='configcontext')
-        ).order_by('app_label', 'model')
+        for ct in ContentType.objects.public().order_by('app_label', 'model')
     ]