[CRM] onboarding fixes and improvements after user testing

- Task: https://www.odoo.com/web#id=9657&view_type=form&model=project.task&action=333&active_id=248
- Pad: https://pad.odoo.com/p/r.kUSVNAuFbAMb5yqr
Don't worry this is a WIP, code review has not been done yet. But you are right about the modification being useless, probably a typo when developing.