[FW][MERGE] project, hr_expense: Fix several multi-company issues + tests

Purpose
=======

Fix multi-company access issues following the big changes that happened
(the 13.0). Make the usability better in order to avoid potential
multi-company issues for the user.

Specification
=============

Check the related commits to see the different fixes that have been
made. For more information about the technical/functional considerations,
check the related task.

closes odoo/odoo#43321

Taskid: 2088891
Forward-port-of: odoo/odoo#43230
Forward-port-of: odoo/odoo#42418
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>