Alerting: Provisioning API - Notification Policies (#46755)

* Base-line API for provisioning notification policies

* Wire API up, some simple tests

* Return provenance status through API

* Fix missing call

* Transactions

* Clarity in package dependencies

* Unify receivers in definitions

* Fix issue introduced by receiver change

* Drop unused internal test implementation

* FGAC hooks for provisioning routes

* Polish, swap names

* Asserting on number of exposed routes

* Don't bubble up updated object

* Integrate with new concurrency token feature in store

* Back out duplicated changes

* Remove redundant tests

* Regenerate and create unit tests for API layer

* Integration tests for auth

* Address linter errors

* Put route behind toggle

* Use alternative store API and fix feature toggle in tests

* Fixes, polish

* Fix whitespace

* Re-kick drone

* Rename services to provisioning

pkg/services/ngalert/api/authorization.go

@@ -179,6 +179,13 @@ func (api *API) authorize(method, path string) web.Handler {
 		http.MethodPost + "/api/v1/ngalert/admin_config",
 		http.MethodGet + "/api/v1/ngalert/alertmanagers":
 		return middleware.ReqOrgAdmin
+
+	// Grafana-only Provisioning Read Paths
+	case http.MethodGet + "/api/provisioning/policies":
+		return middleware.ReqSignedIn
+
+	case http.MethodPost + "/api/provisioning/policies":
+		return middleware.ReqEditorRole
 	}
 
 	if eval != nil {