[crm] implementation planner

- Task: https://www.odoo.com/web/#id=8592&view_type=form&model=project.task&menu_id=3942&action=327
- Pad: https://pad.odoo.com/p/r.4BHh6hQdZ4GPR2qE
fetching all the planner should be done in the show_application method of webclient. For now, each time you click on a menu, this is called.
It would perhaps make more sence to store the planner list on a planner obj, rather than on the web.Menu