[FIX] stock: display the available qty in `stock.quant` form view

Steps to reproduce the bug:
- Create a storable product “P1”
- update the quantity to 10
- Go to inventory > configuration > warehouse Management > location
- Select your location > current stock
- Search the Product “P1”

Problem:
In `stock.quant’ list view > the available qty is displayed, but if you
click on the line, the available qty is not displayed in the form view,
only the qty counted is displayed

opw-3018469

closes odoo/odoo#103553

Signed-off-by: Steve Van Essche <svs@odoo.com>