Bug 34022: Adjust items data structure

Bug 34022: Adjust items data structure

When creating items at receiving, the generated data structure didn't
match what the code expected, so this patch adapts the code to match the
new data structure introduced by bug 8179.

Once I fixed that, I noticed that the $.ajax request payload, when it
contains an array parameter, it renames it like `param[]`. So the
finishreceive.pl controller is adjusted to this behaviour for the 'on
receiving' use case.

To test:
1. Apply this patch
2. Create a basket with 'create items on receive'
3. Create an order line
4. Close basket
5. Receive shipment
6. Enter invoice number
7. Click on Receive link in the table
8. Fill out item form, make sure all mandatory fields are set
9. Save
10. Verify that the order line is marked as 'received'
11. Verify that there item is created on the record
=> SUCCESS: Works as expected
12. Sign off :-D

Signed-off-by: Michaela Sieber <michaela.sieber@kit.edu>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>