Alerting: Add endpoint for querying state history (#62166)

* Define endpoint and generate

* Wire up and register endpoint

* Cleanup, define authorization

* Forgot the leading slash

* Wire up query and SignedInUser

* Wire up timerange query params

* Add todo for label queries

* Drop comment

* Update path to rules subtree

pkg/services/ngalert/api/api.go

@@ -84,6 +84,7 @@ type API struct {
 	AlertsRouter         *sender.AlertsRouter
 	EvaluatorFactory     eval.EvaluatorFactory
 	FeatureManager       featuremgmt.FeatureToggles
+	Historian            Historian
 
 	AppUrl *url.URL
 }
@@ -152,6 +153,11 @@ func (api *API) RegisterAPIEndpoints(m *metrics.API) {
 		muteTimings:         api.MuteTimings,
 		alertRules:          api.AlertRules,
 	}), m)
+
+	api.RegisterHistoryApiEndpoints(NewStateHistoryApi(&HistorySrv{
+		logger: logger,
+		hist:   api.Historian,
+	}), m)
 }
 
 func (api *API) Usage(ctx context.Context, scopeParams *quota.ScopeParameters) (*quota.Map, error) {