Alerting: Implement /status for the notification system (#33227)

* Alerting: Implement /status for the notification system

Implements the necessary plumbing to have a /status endpoint on the
notification system.

* Add API examples

* Update API specs

* Update prometheus/common dependency

Co-authored-by: Sofia Papagiannaki <sofia@grafana.com>

pkg/services/ngalert/api/generated_base_api_alertmanager.go

@@ -26,6 +26,7 @@ type AlertmanagerApiService interface {
 	RouteDeleteSilence(*models.ReqContext) response.Response
 	RouteGetAMAlertGroups(*models.ReqContext) response.Response
 	RouteGetAMAlerts(*models.ReqContext) response.Response
+	RouteGetAMStatus(*models.ReqContext) response.Response
 	RouteGetAlertingConfig(*models.ReqContext) response.Response
 	RouteGetSilence(*models.ReqContext) response.Response
 	RouteGetSilences(*models.ReqContext) response.Response
@@ -81,6 +82,15 @@ func (api *API) RegisterAlertmanagerApiEndpoints(srv AlertmanagerApiService, m *
 				m,
 			),
 		)
+		group.Get(
+			toMacaronPath("/api/alertmanager/{Recipient}/api/v2/status"),
+			metrics.Instrument(
+				http.MethodGet,
+				"/api/alertmanager/{Recipient}/api/v2/status",
+				srv.RouteGetAMStatus,
+				m,
+			),
+		)
 		group.Get(
 			toMacaronPath("/api/alertmanager/{Recipient}/config/api/v1/alerts"),
 			metrics.Instrument(