In the detail of an order (SalesOrder/Show), when the order already has delivery assigned, add a direct link to the corresponding delivery (s).

Currently, the reverse link does exist (from delivery to order), but from the order there is no way to navigate to the delivery without searching for it manually.

It's a simple change: show the link when AssignedDelivery is true.

Requested by Gabriel (Commercial Director) — helps to shorten navigation.