[FIX] account_payment: validate s2s payment transaction

- If a customer pays an invoice using a credit card, the payment is
  taken in account but the invoice validation isn't processed until the
  Payment Processing cron do it.

  We want the invoice to be validated as soon as possible.
  To do so, we need to redirect the customer on the payment processing
  page that take cares of validating the payments.

  OPW-1913876

closes odoo/odoo#30217

addons/account_payment/controllers/payment.py

@@ -77,11 +77,11 @@ class PaymentPortal(http.Controller):
         vals = {
             'payment_token_id': token.id,
             'type': 'server2server',
-            'return_url': success_url,
+            'return_url': _build_url_w_params(success_url, params),
         }
 
         tx = invoice_sudo._create_payment_transaction(vals)
         PaymentProcessing.add_payment_transaction(tx)
 
         params['success'] = 'pay_invoice'
-        return request.redirect(_build_url_w_params(success_url, params))
+        return request.redirect('/payment/process')