User can go back to fallback url with payment pending in the app

If user is placing order on desktop and have chosen Vipps/Hurtigkasse payment gateway, landing page shows up where user can input phone number, and trigger app payment. Once payment is pending in the app the landing page can still be "canceled", meaning user will be taken over to the fallback URL but payment status won't change - it will be kept in INITIATE state until it times out, gets approved or cancelled in the app. Currently status INITIATE in onReturn callback is considered incorrect and payment is marked as failed which, according to Vipps support must not happen until order log is updated with either CANCEL or RESERVE/SALE status. The latter is considered as successful payment.