New endpoints: Backorder, print pdf from order, delivery note and quote

Backorder:
If an existing order has a delivered quantity that is smaller than the ordered quantity, this endpoint will take the order id and automatically create a backorder for the remaining amount. The order must be in status shipped or invoiced and may not have an existing backorder already.

Changelog

  • added: POST /v2/orders/{id}/backorder
  • added: GET /v2/orders/{id}/print
  • added: GET /v2/orders/{id}/deliverynote/print
  • added: GET /v2/quotes/{id}/print