go back button in payment window

[MortenTh]

When a payment fails and can be retried it would help with a button for "go back to payment window" from the error message site.
Old quickpay/quickpay issue https://github.com/QuickPay/quickpay/issues/432

[ssandgren]

also if you use a Visa card, when the payment is locked to dankort, we could show a better error message and help the customers better.

This does not help much: