[FIX] stock: issue #3562 - tax and discount not carried over to the extra move

Apparently some fields were missing when creating the extra move object for it to be processed correctly by the invoicing module. This fixes the issue by inheriting links from the original move.

Rel to: #3562 
Disregarding the changes I made earlier, adding the snippet below solves the issue effectively, would you consider this enough to mark this issue fixed or do you have some other ideas?

``` python
if op.linked_move_operation_ids:
    move = op.linked_move_operation_ids[-1].move_id
    res['procurement_id'] = move.procurement_id.id
```