[IMP] status of contract on task, issue and sale order

- Task: https://www.odoo.com/web#id=9258&view_type=form&model=project.task&menu_id=3942&action=327
- Pad: https://pad.odoo.com/p/r.6XynUXUW6cac35nF
It should contract and contract.partner_id...., note that project_id field is not mandatory in task form