Master warning message account yti

- Task: https://www.odoo.com/web#id=9437&view_type=form&model=project.task&action=333&active_id=248
- Pad: https://pad.odoo.com/p/r.wWl3csfJGZ81mgG4
Instead of an hardcoded 'insertOr' adding an 'Or' after the first button, couldn't we add directly in the buttons description something like text_before and text_after ? This way we have something a bit more easy to tweak.