This change makes Odoo’s logging system easier to customize, allowing businesses and developers to define logging behavior in a more standard and flexible way. It also fixes an issue where custom log levels could be misread, which helps keep log output and configuration consistent.

Stable friendly backport of #270562

Less elements where moved, cleaned, removed, ... keeping the minimal changes to make it work in stable.

Forward-Port-Of: odoo/odoo#273127