Add in_stock_quantity to the Products API

I would like the API to be able to update the in_stock_quantity.

The reason is that I currently have auto-update products disabled because that works best for our workflow. However, this means that when I create new Purchase Orders, the stock quantity does not update.

If there was an option to only disable Auto-update products for invoices, that would be great. However, I still would like to be able to update the stock quantity via an API because I heavily use APIs to automate processes.

Thank you!