Can't cancel an order with a refund

[travisp]

This is using solidus_gateway with Stripe, so I'm not sure if it's ultimately an issue with solidus_gateway or solidus, but:

If an order has a refund, and then an attempt to cancel the order is made, the cancellation fails with the error that a charge has already been refunded, because the payment is still marked as completed (even if it was refunded in full).

I'm not fully sure what the expected behavior here is, but after a refund has happened, it becomes impossible to cancel the order itself.