Closes #11738: Annotate utilization on VLAN groups (#13108)

* Update serializers.py

* Update vlans.py

* Update vlans.py

* Update vlangroup.html

* Update vlans.py

* Update vlans.py

* Update serializers.py

* adds db annotation to calculate utilization

* optimize queries

* merge fix

* adds round function for utilization to limit decimal

* fixed object view annotation

* consolidated queryset for utilization

* lint fixes

* Renamed manager method to annotate_utilization() for consistency with other managers

---------

Co-authored-by: Abhimanyu Saharan <desk.abhimanyu@gmail.com>

netbox/templates/ipam/vlangroup.html

@@ -42,6 +42,10 @@
             <th scope="row">Permitted VIDs</th>
             <td>{{ object.min_vid }} - {{ object.max_vid }}</td>
           </tr>
+          <tr>
+            <th scope="row">Utilization</th>
+            <td>{% utilization_graph object.utilization %}</td>
+          </tr>
         </table>
       </div>
     </div>