Fixes #18978 - Allow filtering of Interfaces in the GUI by 802.1Q Mode (#19183)

* feat(dcim): Add VLAN mode filter to CommonInterface

Introduces a new FilterSet for VLAN mode in CommonInterfaceFilterSet.
This allows filtering interfaces based on their VLAN mode using defined
choices.

* feat(dcim): Add VLAN mode filter to Interface FilterForm

Add a field to InterfaceFilterSet to filter interfaces by 802.1Q VLAN
mode.

* feat(virtualization): Add VLAN mode filter to VMInterface

Add a field to VMInterfaceFilterSet to filter interfaces by 802.1Q VLAN
mode.

* fix(dcim): Correct mode filter parameter type in tests

Updates the `mode` filter parameter to accept a list instead of a single
value in `test_filtersets.py`. Ensures proper count assertion for
accurate test behavior.

* feat(virtualization): Add tests for VLAN mode filtering

Introduces tests to validate filtering by `mode` for VMInterface.
Ensures correct filtering for 802.1Q VLAN mode.

* refactor(virtualization): Reorganize FieldSets in FilterSets

Splits the 'Attributes' FieldSet into two distinct FieldSets for better
clarity: 'Attributes' and 'Addressing'. This improves form organization
and makes it more intuitive for users.

netbox/dcim/filtersets.py

@@ -1689,6 +1689,10 @@ class MACAddressFilterSet(NetBoxModelFilterSet):
 
 
 class CommonInterfaceFilterSet(django_filters.FilterSet):
+    mode = django_filters.MultipleChoiceFilter(
+        choices=InterfaceModeChoices,
+        label=_('802.1Q Mode')
+    )
     vlan_id = django_filters.CharFilter(
         method='filter_vlan_id',
         label=_('Assigned VLAN')