[IMP] hr_expense: allow default for the company journal

Revision 26a5653f introduced
the possibility to set up a default journal for accounting
entries created by "employee-paid" expenses

This commit adds the same possibility for the "company-paid"
expenses (because why allow it for one and not the other?).

closes odoo/odoo#99993

Signed-off-by: Kevin Baptiste <kba@odoo.com>