chore: further cleanup and refactor

src/BusProNet/Model/Booking.php

@@ -15,6 +15,8 @@ use App\BusProNet\Constants;
  */
 class Booking
 {
+    public const string STATUS_CANCELED = 'S';
+
     public ?int $id = null;
     public ?int $agencyId = null;
     public ?int $bookingNumber = null;