[CHORE]: Implement receive_notification function in Notification service

src/service/notification.rs

@@ -91,4 +91,9 @@ impl NotificationService {
             ))  
         }
     }
+
+    pub fn receive_notification(payload: Notification) -> Result<Notification> {
+        let subscriber_result: Notification = NotificationRepository::add(payload);
+        return Ok(subscriber_result);
+    }
 }
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