As a librarian, I want to be able to delete documents even if order lines are still attached.

Acceptance criteria

• I can delete a document if all can_delete criteria are met and if all attached order_lines have statuts recieved or cancelled.
• When displaying orders and order lines in the pro view, prevent errors if the UI needs info from the document. If the linked document doesn't exist, replace document title by [pid:XXXX]:
  • Orders brief and detailed views:
  • Order line (edit + recieve views)