Alerting: Protected fields for Contact points (#115442)

* Alerting: Protect sensitive fields of contact points from
 unauthorized modification

- Introduce a new permission alert.notifications.receivers.protected:write. The permission is granted to contact point administrators.
- Introduce field Protected to NotifierOption
- Introduce DiffReport for models.Integrations with focus on Settings. The diff report is extended with methods that return all keys that are different between two settings.
- Add new annotation 'grafana.com/access/CanModifyProtected' to Receiver model
- Update receiver service to enforce the permission and return status 403 if unauthorized user modifies protected field
- Update receiver testing API to enforce permission and return status 403 if unauthorized user modifies protected field.
- Update UI to disable protected fields if user cannot modify them

pkg/registry/apps/alerting/notifications/receiver/conversions.go

@@ -110,10 +110,11 @@ func convertToK8sResource(
 }
 
 var permissionMapper = map[ngmodels.ReceiverPermission]string{
-	ngmodels.ReceiverPermissionReadSecret: "canReadSecrets",
-	ngmodels.ReceiverPermissionAdmin:      "canAdmin",
-	ngmodels.ReceiverPermissionWrite:      "canWrite",
-	ngmodels.ReceiverPermissionDelete:     "canDelete",
+	ngmodels.ReceiverPermissionReadSecret:      "canReadSecrets",
+	ngmodels.ReceiverPermissionAdmin:           "canAdmin",
+	ngmodels.ReceiverPermissionWrite:           "canWrite",
+	ngmodels.ReceiverPermissionDelete:          "canDelete",
+	ngmodels.ReceiverPermissionModifyProtected: "canModifyProtected",
 }
 
 func convertToDomainModel(receiver *model.Receiver) (*ngmodels.Receiver, map[string][]string, error) {