Partner Request Add Another Item auto-populates with first item when returning from failed validation

Initial state:

Org with request units (e.g., the default units + pallets) for ItemA
Logged in as verified partner

Steps:

1. Click Create Request (under the Quantity category)
2. Enter 3 and pallets for ItemA
3. Click Add Another Item
4. Enter 5 and units for ItemA
5. Click Submit Essentials Request (this will be rejected since we don't support mixing units for an item in a single request)
6. Click Add Another Item

What I see:
The newly added item is populated with the data from the first entry in the list (3 pallets of ItemA)

What I expect to see:
No item selected from dropdown and no quantity entered on the newly added item

Reproduce the flow from Create Request under the Quantity category, including the failed mixed-unit submission and the second Add Another Item action. Inspect the request form's item-addition and validation-return behavior; done means a newly added item has an empty item dropdown and quantity after validation fails.