Add support for native Shopware refunds

[chris-returnless]

Shopware has a commercial plan (Rise) where merchants are able to process refunds. The benefit of this feature is that you can use both the Shopware panel and the Shopware API to create refunds.

Here is the endpoint that we use:
https://shopware.stoplight.io/docs/admin-api/948f118f2363e-create-a-new-order-return-resources

In this endpoint, it's possible to issue a refund via lineItems.refundAmount. In Shopware, this refund is registered correctly. However, the Adyen integration does not seem to listen to this refund request, and therefore does not execute the refund. See screenshots attached.

Can you let us know if the Adyen integration can be made compatible with Shopware's default Refund feature?

Thanks in advance for your thoughts!