[FIX] web_editor,website,website_sale : fix products header edition

Prevent edition on e-commerce products header bar.
Since we cannot save any change done in the header object anyway,
And some edition would trigger error.
We put the all bar in a read-only mode.

task-2745151

X-original-commit: e2f7b8fa
Part-of: odoo/odoo#91840