[FIX] project timesheet: Open task without timesheet rights

Before this commit:
If you have not at least the timesheet user right, you can't open
project task as a field in not present in the view.

After this commit:
You can open the task view

closes odoo/odoo#41229

Taskid: 2148606
Related: odoo/enterprise#6984
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>