refs(alert_rules): Move incident related endpoints into the incidents module (#18956)

I've been meaning to do this for a while, and since I'm already refactoring things this seems like a
good time. This puts all incident related endpoints into the `incidents` module. This means that the
majority of incidents code is located here. The only thing we're missing are the serializers, which
are hard to move out due to how the api module is structured. We can likely refactor things there
at some point so that we can get everything into the one place.

src/sentry/api/urls.py

@@ -98,19 +98,6 @@ from .endpoints.organization_events_meta import (
 )
 from .endpoints.organization_events_stats import OrganizationEventsStatsEndpoint
 from .endpoints.organization_group_index import OrganizationGroupIndexEndpoint
-from .endpoints.organization_incident_activity_index import (
-    OrganizationIncidentActivityIndexEndpoint,
-)
-from .endpoints.organization_incident_comment_details import (
-    OrganizationIncidentCommentDetailsEndpoint,
-)
-from .endpoints.organization_incident_comment_index import OrganizationIncidentCommentIndexEndpoint
-from .endpoints.organization_incident_details import OrganizationIncidentDetailsEndpoint
-from .endpoints.organization_incident_index import OrganizationIncidentIndexEndpoint
-from .endpoints.organization_incident_seen import OrganizationIncidentSeenEndpoint
-from .endpoints.organization_incident_subscription_index import (
-    OrganizationIncidentSubscriptionIndexEndpoint,
-)
 from .endpoints.organization_index import OrganizationIndexEndpoint
 from .endpoints.organization_integration_details import OrganizationIntegrationDetailsEndpoint
 from .endpoints.organization_integration_repos import OrganizationIntegrationReposEndpoint
@@ -311,7 +298,24 @@ from sentry.incidents.endpoints.project_alert_rule_index import (
     ProjectAlertRuleIndexEndpoint,
     ProjectCombinedRuleIndexEndpoint,
 )
+from sentry.incidents.endpoints.organization_incident_activity_index import (
+    OrganizationIncidentActivityIndexEndpoint,
+)
+from sentry.incidents.endpoints.organization_incident_comment_details import (
+    OrganizationIncidentCommentDetailsEndpoint,
+)
+from sentry.incidents.endpoints.organization_incident_comment_index import (
+    OrganizationIncidentCommentIndexEndpoint,
+)
+from sentry.incidents.endpoints.organization_incident_details import (
+    OrganizationIncidentDetailsEndpoint,
+)
+from sentry.incidents.endpoints.organization_incident_index import OrganizationIncidentIndexEndpoint
+from sentry.incidents.endpoints.organization_incident_seen import OrganizationIncidentSeenEndpoint
 from sentry.incidents.endpoints.organization_incident_stats import OrganizationIncidentStatsEndpoint
+from sentry.incidents.endpoints.organization_incident_subscription_index import (
+    OrganizationIncidentSubscriptionIndexEndpoint,
+)
 
 # issues endpoints are available both top level (by numerical ID) as well as coupled
 # to the organization (and queryable via short ID)