It's not entirely clear whether `@synchronized` is even useful, but
keep it for now. `locked` is just the default instance of
`@synchronised`.
- rewrite `@synchronized` using `decorator`, don't fold everything
into a single call as there's a potential for parametric conflict
- remove the independent `locked` in `sql_db.py`
- convert `lru` to `locked`
- move `Registry` over to `locked` where applicable
closesodoo/odoo#82718
Signed-off-by: Raphael Collet <rco@odoo.com>