[ADD]planner,planner_crm: created new feature planner tool (CRM planner) which help to plan the implementation of users.

- Task: https://www.odoo.com/web#id=8592&view_type=form&model=project.task
- Pad: https://pad.odoo.com/p/r.4BHh6hQdZ4GPR2qE
Some docstrings would be welcome here.