Implement receive_notification function in Notification service.

src/service/notification.rs

@@ -93,4 +93,9 @@ impl NotificationService {
             .join()
             .unwrap();
     }
+
+    pub fn receive_notification(payload: Notification) -> Result<Notificition> {
+        let subscriber_result: Notification = NotificationRepository::add(payload);
+        return Ok(subscriber_result);
+    }
 }