[17.0] [IMP] account_payment_purchase: let indivual partners have bank accounts in puchase

[Tisho99]

In the vendor bills of the base account module you can select any bank account that belongs to the vendor company, even if the selected vendor is an individual contact of the company.

I think that the bank account field in the purchase should behave the same way. Currently you can not select a bank account if the selected vendor is an individual.

Links of account module:

https://github.com/odoo/odoo/blob/1df4efd64c353bbc6b21f01b7ef12308bdfc9780/addons/account/models/account_move.py#L333 https://github.com/odoo/odoo/blob/1df4efd64c353bbc6b21f01b7ef12308bdfc9780/addons/account/views/account_move_views.xml#L937 https://github.com/odoo/odoo/blob/1df4efd64c353bbc6b21f01b7ef12308bdfc9780/addons/account/models/account_move.py#L1406

T-6102