Alerting: New feature toggle for enabling standalone alerts (#25984)

* Add feature toggle for standalone alerts

* Add IsStandaloneAlertsEnabled exported func

packages/grafana-data/src/types/config.ts

@@ -41,6 +41,7 @@ export interface FeatureToggles {
   meta: boolean;
   datasourceInsights: boolean;
   reportGrid: boolean;
+  standaloneAlerts: boolean;
 }
 
 /**

packages/grafana-runtime/src/config.ts

@@ -55,6 +55,7 @@ export class GrafanaBootConfig implements GrafanaConfig {
     meta: false,
     datasourceInsights: false,
     reportGrid: false,
+    standaloneAlerts: false,
   };
   licenseInfo: LicenseInfo = {} as LicenseInfo;
   rendererAvailable = false;