AlertNotifications: Translate notifications IDs to UIDs in Rule builder (#19882)

* AlertNotifications: Translate notifications IDs to UIDs in alert Rule builder

* Avoid shadowing errors, raise validation error on non-existing notification id

* create a cache for notification Uids to minimize db overhead

* add cache usage test

* avoid caching empty notification Uids

* isolate db in alert notificationUid caching tests

pkg/models/alert_notifications.go

@@ -91,6 +91,13 @@ type DeleteAlertNotificationWithUidCommand struct {
 	OrgId int64
 }
 
+type GetAlertNotificationUidQuery struct {
+	Id    int64
+	OrgId int64
+
+	Result string
+}
+
 type GetAlertNotificationsQuery struct {
 	Name  string
 	Id    int64