[FIX] purchase: fix bank info on vendor bill based on po

Steps to reproduce:

        - Install puchases, accounting, contact
        - Create a new company with a bank account
        - Create a new person contact linked to the previous company
        - Make a purchase order from that person
        - Make a vendor bill using the auto-complete as the previous PO

Issue:

        The bank account field is not filled

Cause:

        The _prepare_invoice function tries to grab the bank information
        from the contact on the PO. But in the case of a person of a company,
        this information is stored in the parent company. Resulting in an empty
        value

Solution:

        Use the field "comercial_partner_id" to get the bank id. As this field
	will use the parent company if the current partner is a person.

opw-2849706

closes odoo/odoo#93487

X-original-commit: c5f94e84dd5d6ec108484425d348053961bd13ff
Signed-off-by: Grazioso Andrea (agr) <agr@odoo.com>
Signed-off-by: Vranckx Florian (flvr) <flvr@odoo.com>

addons/purchase/models/purchase.py

@@ -607,7 +607,8 @@ class PurchaseOrder(models.Model):
             raise UserError(_('Please define an accounting purchase journal for the company %s (%s).') % (self.company_id.name, self.company_id.id))
 
         partner_invoice = self.env['res.partner'].browse(self.partner_id.address_get(['invoice'])['invoice'])
-        partner_bank_id = self.partner_id.bank_ids.filtered_domain(['|', ('company_id', '=', False), ('company_id', '=', self.company_id.id)])[:1]
+        partner_bank_id = self.partner_id.commercial_partner_id.bank_ids.filtered_domain(['|', ('company_id', '=', False), ('company_id', '=', self.company_id.id)])[:1]
+
         invoice_vals = {
             'ref': self.partner_ref or '',
             'move_type': move_type,