On receiving a serial in the serials module, it would be helpful to add the id of the vendor automatically to the item
In 952 $e (Source of acquisition), if the subscription is set to "create an item record", 
and the subscription has a vendor. 
Similar to the acquisition module, where the vendor is already added automatically to the items.

To test:
1. If necessary, set 952 $e in the bibliographic framework to visible in the staff interface and the editor.
2. Go to serials
3. Create a subscription with a vendor and the setting “create an item record” and save it.
4. Go to serial collection.
5. Set a serial issue from status “Expected” to “Arrived”
6. The vendor in subfield “e” (Source of acquisition) in the item form is empty. But it would be nice if the vendor was filled in automatically.