[FIX] point_of_sale: enable report generation with multi bank payments

Following commit https://github.com/odoo/odoo/commit/d9190e34543c4a1151656859acb41556bcb3a364, generating a sale report became
impossible if a session had more than one account payment.
This was due to a ValueError: Expected singleton.

opw-3799171

closes odoo/odoo#157691

X-original-commit: eade8f182b4e4676feff61e3ec24e38ae6641985
Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>
Signed-off-by: Pedram Bi Ria (pebr) <pebr@odoo.com>

addons/point_of_sale/models/report_sale_details.py

@@ -149,7 +149,7 @@ class ReportSaleDetails(models.AbstractModel):
                         elif payment['id'] in account_payments.mapped('pos_payment_method_id.id'):
                             account_payment = account_payments.filtered(lambda p: p.pos_payment_method_id.id == payment['id'])
                             payment['final_count'] = payment['total']
-                            payment['money_counted'] = account_payment.amount
+                            payment['money_counted'] = sum(account_payment.mapped('amount'))
                             payment['money_difference'] = payment['money_counted'] - payment['final_count']
                             payment['cash_moves'] = []
                             if payment['money_difference'] > 0: