Rework of the hr.expense workflow so that:
- expenses paid by employee generate purchase.order
- expenses paid by company generate entry that look like payments
Main reason being that purchase.receipt are not active by default.
That makes the entry hard to find, holes in sequences, inconsitency
with payment states.
It also remove the refusal of expenses as this was dead / inaccessible code, only reports can be refused.
task-id: 3126550
[community](https://github.com/odoo/odoo/pull/110518)
[enterprise](https://github.com/odoo/enterprise/pull/36090)
closesodoo/odoo#110518
Related: odoo/upgrade#4266
Related: odoo/enterprise#36090
Signed-off-by: Laurent Smet <las@odoo.com>