Saves changes to an order and records a draft save in the order's history. The order's status doesn't change.

This works like Update order, with the same body and the same rules:

• The lines you send replace all the current lines.
• The amounts you send are saved as they are.
• Leave out tag_list and all tags are removed.
• order_type must be the order's current type. currency, customer_id and status are ignored.

To save without changing anything, get the order and send its current lines, figures and tags back.