[Alerting]: Several modifications in alert rules (#32983)

* [Alerting]: Use common properties for all rules

* Add Labels in rules

* Fix update ruleGroup API

Return 400 Bad Request response
when the request contains a UID that does not exist

* Check permissions and return namespace id

* Apply suggestions from code review

Co-authored-by: gotjosh <josue@grafana.com>

pkg/services/ngalert/api/api_prometheus.go

@@ -100,7 +100,7 @@ func (srv PrometheusSrv) RouteGetRuleStatuses(c *models.ReqContext) response.Res
 				State:       "inactive",
 				Name:        rule.Title,
 				Query:       "", // TODO: get this from parsing AlertRule.Data
-				Duration:    time.Duration(rule.For).Seconds(),
+				Duration:    rule.For.Seconds(),
 				Annotations: rule.Annotations,
 			}