Fixes #18245: Make DeviceRole Hierarchical (#19008)

Made DeviceRoles hierarchical, had to also change the filtersets for Device, ConfigContext and VirtualMachine to use the TreeNodeMultipleChoiceFilter.

Note: The model was changed to use NestedGroupModel, a side-effect of this is it also adds comments field, but I thought that was better then doing a one-off just for DeviceRole and having to define the fields, validators, etc.. - keeps everything DRY / consistent.

* 18981 Make Device Roles Hierarchical

* 18981 forms, serializer

* 18981 fix tests

* 18981 fix tests

* 18981 fix tests

* 18981 fix tests

* 18981 fix tests

* 18981 fix migration merge

* 18981 fix tests

* 18981 fix filtersets

* 18981 fix tests

* 18981 comments

* 18981 review changes

netbox/virtualization/filtersets.py

@@ -171,13 +171,15 @@ class VirtualMachineFilterSet(
     name = MultiValueCharFilter(
         lookup_expr='iexact'
     )
-    role_id = django_filters.ModelMultipleChoiceFilter(
+    role_id = TreeNodeMultipleChoiceFilter(
         queryset=DeviceRole.objects.all(),
+        lookup_expr='in',
         label=_('Role (ID)'),
     )
-    role = django_filters.ModelMultipleChoiceFilter(
-        field_name='role__slug',
+    role = TreeNodeMultipleChoiceFilter(
+        field_name='role',
         queryset=DeviceRole.objects.all(),
+        lookup_expr='in',
         to_field_name='slug',
         label=_('Role (slug)'),
     )

netbox/virtualization/tests/test_filtersets.py

@@ -294,7 +294,8 @@ class VirtualMachineTestCase(TestCase, ChangeLoggedFilterSetTests):
             DeviceRole(name='Device Role 2', slug='device-role-2'),
             DeviceRole(name='Device Role 3', slug='device-role-3'),
         )
-        DeviceRole.objects.bulk_create(roles)
+        for role in roles:
+            role.save()
 
         devices = (
             create_test_device('device1', cluster=clusters[0]),

netbox/virtualization/tests/test_views.py

@@ -203,7 +203,8 @@ class VirtualMachineTestCase(ViewTestCases.PrimaryObjectViewTestCase):
             DeviceRole(name='Device Role 1', slug='device-role-1'),
             DeviceRole(name='Device Role 2', slug='device-role-2'),
         )
-        DeviceRole.objects.bulk_create(roles)
+        for role in roles:
+            role.save()
 
         platforms = (
             Platform(name='Platform 1', slug='platform-1'),