Klarna payment workflow

Both Part Payment and Invoice payment methods have the same request flow. It basically consists of the following steps:

• Pre-check: reserves the amount of the purchase.
• Check order status: checks if the order status is pending accepted. If it’s not, OMS waits for 2 hours and then calls again KlarnaApi to retrieve the status of the order. In case the status is denied the order is canceled.
• Capture payment: activates the reservation that corresponds to the given reference number.
• Update payment: if activation fails, we need to update the reservation that corresponds to the given reference number.
• Refund: performs a partial refund.
• Cancel: cancels a reservation.