[Accounting] revenue recognition

- Task: https://www.odoo.com/web?#id=6357&view_type=form&model=project.task&action=333&active_id=131
- Pad: https://pad.odoo.com/p/r.n8sCRDTVK3sqmxsV
use xmlid_to_res_id or ref() from the new api.