Handling Pre-registration number

For Royal Mail international shipments, pre-registration values (such as IOSS or PRS) sourced from Customs Settings are now applied only when supported by the selected service and destination. If the selected route does not support the preregistration type, the value is no longer applied and the shipment is processed without validation errors.

This update prevents valid shipments from being rejected due to unsupported preregistration data and ensures successful shipment creation where applicable.