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/models/provisioning.go

@@ -14,3 +14,9 @@ type Provisionable interface {
 	ResourceID() string
 	ResourceOrgID() int64
 }
+
+// ProvisionableInOrg represents a resource that can be provisioned, given external org-related information.
+type ProvisionableInOrg interface {
+	ResourceType() string
+	ResourceID() string
+}