Feature Request: Support VAT Number functionality for Backend Draft Orders

Currently, the app only works on the frontend. This means the VAT number is only added to the order when the customer creates the order themselves and has entered (or has) a VAT number.

However, we would like to request support for backend-created orders as well. Specifically, when an employee creates a draft order in the backend on behalf of a customer who has a VAT number, the VAT number should also be included on the order.

This would ensure consistency between frontend and backend order creation and improve workflows for merchants who manually create orders for customers.