Closes #13283: Add context to dropdown options (#15104)

* Initial work on #13283

* Enable passing TomSelect HTML template attibutes on DynamicModelChoiceField

* Merge disabled_indicator into option_attrs

* Add support for annotating a numeric count on dropdown options

* Annotate parent object on relevant fields

* Improve rendering of color options

* Improve rendering of color options

* Rename option_attrs to context

* Expose option context on ObjectVar for custom scripts

* Document dropdown context variables

netbox/ipam/forms/model_forms.py

@@ -267,14 +267,20 @@ class IPRangeForm(TenancyForm, NetBoxModelForm):
 
 class IPAddressForm(TenancyForm, NetBoxModelForm):
     interface = DynamicModelChoiceField(
-        label=_('Interface'),
         queryset=Interface.objects.all(),
         required=False,
+        context={
+            'parent': 'device',
+        },
         selector=True,
+        label=_('Interface'),
     )
     vminterface = DynamicModelChoiceField(
         queryset=VMInterface.objects.all(),
         required=False,
+        context={
+            'parent': 'virtual_machine',
+        },
         selector=True,
         label=_('Interface'),
     )