make sendTo optional and add enableNotification to models

Author: andrii-i

src/model.ts

@@ -75,7 +75,8 @@ export type ModelWithScheduleFields = {
 };
 
 export type Notification = {
-  sendTo: string;
+  sendTo?: string;
+  enableNotification?: boolean;
   availableEvents?: string[];
   selectedEvents?: string[];
 };