[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
Put those 3 lines in a function update_ui_progress_bar, since the same lines are in the 'mark_as_done' method.
Then, declare the attribute this.set("progress", 0) in `init` and add an listener `this.on("change:progress", this, this.update_ui_progress_bar)` in the start method. With that, every time you will set a new value in this.progress, the update_ui_progress_bar function will be trigger, and the progress bar will be updated ;)