8927 plugin search (#10489)

* #7016 base search classes

* 7016 add search indexes

* 7016 add search indexes

* 7016 add search indexes

* 7016 add search indexes

* 7016 add search indexes

* 7016 add search indexes

* 8927 refactor search

* 8927 refactor search

* 8927 refactor search

* 8927 refactor search

* 8927 get search choices working

* 8927 cleanup - optimize

* 8927 use backend search function

* 8927 fix for plugin search

* 8927 add docs

* Move search app to a module under netbox/

* Utilize global registry to register model search classes

* Build search form options from registry

* Determine search categories from model app by default

* Enable dynamic search registration for plugins

* Update docs & improve plugin support

* Clean up search backend class

* Docs for #8927

Co-authored-by: jeremystretch <jstretch@ns1.com>

netbox/circuits/search.py

@@ -0,0 +1,34 @@
+import circuits.filtersets
+import circuits.tables
+from circuits.models import Circuit, Provider, ProviderNetwork
+from netbox.search import SearchIndex, register_search
+from utilities.utils import count_related
+
+
+@register_search()
+class ProviderIndex(SearchIndex):
+    model = Provider
+    queryset = Provider.objects.annotate(count_circuits=count_related(Circuit, 'provider'))
+    filterset = circuits.filtersets.ProviderFilterSet
+    table = circuits.tables.ProviderTable
+    url = 'circuits:provider_list'
+
+
+@register_search()
+class CircuitIndex(SearchIndex):
+    model = Circuit
+    queryset = Circuit.objects.prefetch_related(
+        'type', 'provider', 'tenant', 'tenant__group', 'terminations__site'
+    )
+    filterset = circuits.filtersets.CircuitFilterSet
+    table = circuits.tables.CircuitTable
+    url = 'circuits:circuit_list'
+
+
+@register_search()
+class ProviderNetworkIndex(SearchIndex):
+    model = ProviderNetwork
+    queryset = ProviderNetwork.objects.prefetch_related('provider')
+    filterset = circuits.filtersets.ProviderNetworkFilterSet
+    table = circuits.tables.ProviderNetworkTable
+    url = 'circuits:providernetwork_list'