Closes #15131: Dynamic queryset annotations for REST API endpoints (#15152)

* Introduce RelatedObjectCountField

* Introduce get_annotations_for_serializer() and enable dynamic annotations

* Add RelatedObjectCountFields to serializers; remove static annotations from querysets

* Remove annotations cleanup logic from BriefModeMixin

* Annotate type for RelatedObjectCountField

* Remove redundant field on TagSerializer

* Add missing reverse relationship for power feeds to rack

* Refactor RelatedObjectCountField to take a single relationship name

netbox/tenancy/api/views.py

@@ -1,13 +1,8 @@
 from rest_framework.routers import APIRootView
 
-from circuits.models import Circuit
-from dcim.models import Device, Rack, Site
-from ipam.models import IPAddress, Prefix, VLAN, VRF
 from netbox.api.viewsets import NetBoxModelViewSet, MPTTLockedMixin
 from tenancy import filtersets
 from tenancy.models import *
-from utilities.utils import count_related
-from virtualization.models import VirtualMachine, Cluster
 from . import serializers
 
 
@@ -36,18 +31,7 @@ class TenantGroupViewSet(MPTTLockedMixin, NetBoxModelViewSet):
 
 
 class TenantViewSet(NetBoxModelViewSet):
-    queryset = Tenant.objects.annotate(
-        circuit_count=count_related(Circuit, 'tenant'),
-        device_count=count_related(Device, 'tenant'),
-        ipaddress_count=count_related(IPAddress, 'tenant'),
-        prefix_count=count_related(Prefix, 'tenant'),
-        rack_count=count_related(Rack, 'tenant'),
-        site_count=count_related(Site, 'tenant'),
-        virtualmachine_count=count_related(VirtualMachine, 'tenant'),
-        vlan_count=count_related(VLAN, 'tenant'),
-        vrf_count=count_related(VRF, 'tenant'),
-        cluster_count=count_related(Cluster, 'tenant')
-    )
+    queryset = Tenant.objects.all()
     serializer_class = serializers.TenantSerializer
     filterset_class = filtersets.TenantFilterSet