Fixes: #18350 - Remove 'site' and 'provider_network' from CircuitTerminationIndex.display_attrs (#18351)

* Remove 'site' and 'provider_network' from CircuitTerminationIndex.display_attrs

* Use '_site' and '_provider_network' in display_attrs

* Replace private fields with 'termination'

netbox/circuits/search.py

@@ -34,7 +34,7 @@ class CircuitTerminationIndex(SearchIndex):
         ('port_speed', 2000),
         ('upstream_speed', 2000),
     )
-    display_attrs = ('circuit', 'site', 'provider_network', 'description')
+    display_attrs = ('circuit', 'termination', 'description')
 
 
 @register_search