Add MarkSeen Functionality to Notification System

- Implemented the MarkSeen method in the notification client to mark notifications as seen, enhancing user interaction with notifications.
- Added MarkSeenRequest and MarkSeenResponse structs to facilitate the request and response handling for marking notifications.
- Updated the NotificationService interface to include the new MarkSeen method, ensuring consistency across the service layer.
- Enhanced the SDK with a QuickMarkSeen convenience method for easier usage in client applications.
- Included logging for successful and failed attempts to mark notifications as seen, improving traceability and debugging capabilities.

pkg/notification/service.go

@@ -109,6 +109,11 @@ func (s *Service) GetNotifications(ctx context.Context, req *GetNotificationsReq
 	return s.client.GetNotifications(ctx, req)
 }
 
+// MarkSeen marks a notification as seen
+func (s *Service) MarkSeen(ctx context.Context, notificationID string) (*MarkSeenResponse, error) {
+	return s.client.MarkSeen(ctx, notificationID)
+}
+
 // Health checks if the notification service is available
 func (s *Service) Health(ctx context.Context) error {
 	// Create a simple test request to check service availability