Attempting to duplicate request as user appears to fail, creates a request with no position and then breaks duplication for diku_admin

Steps to reproduce:

1. Log into folio-snapshot
2. As diku_admin, create a page request on an available item (I don't think the type of request or fulfillment preference actually matters for this bug)
3. Duplicate that request while logged in as diku_admin just to prove that duplicating it works when logged in as this user
4. Duplicate one of the requests with Hold shelf fulfillment (call it Request 1)
5. Create a new user with Requests: All permissions (I created cboerema)
6. Now log into folio as the other user (cboerema)
7. Go to Requests and open Request 1
8. Select Duplicate from the menu
9. Pick a new requester
10. Attempt to save duplicated request
11. BUG 1: Nothing happens. No message.
12. Close the duplicate form and search for all the requests on the item
13. BUG 2: Note that the request you were just trying to create actually did create but it doesn't have a position in queue
14. Log out and back in as diku_admin and attempt to duplicate Request 1
15. BUG 2: Cant save duplicated request as diku_admin anymore

Expected:

• Should be able to duplicate requests when logged in as user with Requests: All permissions ("Requests: view, create" etc should also allow duplication and I believe they all suffer from this same bug)
• An open request should always have a position in queue
• Failure to duplicate a request when logged in as one user should not affect whether it can be duplicated by another user (it's crazy that this is happening?!)

Actual:

• See bugs in repro steps
• See screencast: https://drive.google.com/file/d/1kbK0kIrJpIJGKoPgNawzBHpNfkLTlQSm/view?usp=sharing

Additional info: When testing this, I came across some other issues

• UIREQ-385 Wrong menus showing when duplicating request when not logged in as diku_admin
• UIREQ-387 Creating request as user other than diku_admin results in "page requests not allowed..." message and then creates anyway