Purchase orders now show the right billing status when goods are only partially received and billed. This prevents partially completed orders from appearing fully billed too early, improving purchasing visibility and reducing follow-up mistakes.

Before this commit
===============
when product quantity partially received and also billed for received quantity
than the PO billing status is 'fully billed' instead of 'nothing to bill'

After this commit
===============
when product quantity partially received and also billed for received quantity
than the PO billing status is 'nothing to bill' and when product quantity fully
received and fully billed, than PO billing status is 'fully billed'.

TaskID: 2682551

This update makes Odoo Studio more resilient when errors occur during app or action editing, returning users to a usable editor instead of leaving the interface broken. It also improves how Studio handles simultaneous state changes and avoids unnecessary reloads, helping users keep their work in progress.