Master event kanban ppa

- Task: https://www.odoo.com/web?&debug=#id=8708&view_type=form&model=project.task&action=333&active_id=131
- Pad: https://pad.odoo.com/p/r.4ziC9amJvS5GLIcm
There is a default graph view on registrations (group by type, row on date). I don't think having two actions is necessary. Could you check to have a unique action with the correct default group bys and measures ?