Item count bug when there are multiple holdings on an instance

Overview: When there are multiple holdings on an instance, and item records are being created, the counts next to each holdings do not increment/decrement properly

Steps to Reproduce:

1. Log into folio-snapshot as diku_admin
2. Go to the Inventory app
3. Click Actions/New, and create a new Instance, with a title and a resource type
4. Click Add holdings and create a new Holdings, with any permanent location
5. Click Add holdings again, and create a second new Holdings, with a different permanent location from the first one
6. Note the number of item records in the little counter next to each closed holdings accordion
7. Click Add item next to the first holdings, and create a new Item with a Barcode, Material type, and Permanent loan type
8. Save the item record and note the number of item records in the little counter next to each closed holdings accordion (should be 1 for first holdings, 0 for second holdings)
9. Click Add item next to the second holdings, and create a new Item with a Barcode, Material type, and Permanent loan type
10. Save the item record and note the number of item records in the little counter next to each closed holdings accordion (should be 1 for first holdings, 1 for second holdings)
11. Click Add item next to the first holdings, and create a second new Item with a Barcode, Material type, and Permanent loan type
12. Save the item record and note the number of item records in the little counter next to each closed holdings accordion (should be 2 for first holdings, 1 for second holdings)
13. Click Add item next to the second holdings, and create a second new Item with a Barcode, Material type, and Permanent loan type
14. Save the item record and note the number of item records in the little counter next to each closed holdings accordion (should be 2 for first holdings, 2 for second holdings)
15. Delete each item record, one at a time, and watch the counter next to each closed holdings accordion

Expected Results: As item records are created and deleted, the item counter next to each holdings should be accurate

Actual Results: The counts stay synchronized with each other as items are added and deleted. When the user expands a holdings accordion, the correct number of item records show under the holdings, but when the accordion is closed, the incorrect count is displayed again

Additional Information: See attached video

NOTE: Be sure to include at least 1 Prokopovych dev as a PR reviewer