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/dcim/forms/bulk_edit.py

@@ -620,6 +620,11 @@ class ModuleTypeBulkEditForm(NetBoxModelBulkEditForm):
 
 
 class DeviceRoleBulkEditForm(NetBoxModelBulkEditForm):
+    parent = DynamicModelChoiceField(
+        label=_('Parent'),
+        queryset=DeviceRole.objects.all(),
+        required=False,
+    )
     color = ColorField(
         label=_('Color'),
         required=False
@@ -639,12 +644,13 @@ class DeviceRoleBulkEditForm(NetBoxModelBulkEditForm):
         max_length=200,
         required=False
     )
+    comments = CommentField()
 
     model = DeviceRole
     fieldsets = (
-        FieldSet('color', 'vm_role', 'config_template', 'description'),
+        FieldSet('parent', 'color', 'vm_role', 'config_template', 'description'),
     )
-    nullable_fields = ('color', 'config_template', 'description')
+    nullable_fields = ('parent', 'color', 'config_template', 'description', 'comments')
 
 
 class PlatformBulkEditForm(NetBoxModelBulkEditForm):