[MERGE] web, *: review crashmanager changes for backend/frontend

* gamification, website_forum, stock

Fix for: https://github.com/odoo/odoo/pull/32132



Some problems with the mentioned PR had to be fixed and after some
discussions, it was decided to revert back to the original crashmanager
warnings for the backend.

See sub-commits for details.

closes odoo/odoo#35209

Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>