[17.0][RFC] Challenge: replace operating units by Odoo branches

[AaronHForgeFlow]

Odoo 17.0 is introducing company branches. The concept is quite similar to Operating units, as long branches is a functional division of the company. Branches can share the same chart of accounts of the company, and have their own access rules, picking operation types, sales teams, so at the end it is the "same" concept than operating units.

The main challenges are:

• [ ] Migrate from operating.unit to company branches (child res.company)
• [ ] Find anything that is not covered in the standard when migrating the modules. E.g. in the account_operating_unit one operating unit should be able to pay invoices from the other and be self-balanced. That should be possible when using branches.

Opinions and ideas are welcome.