[ECP-9488] PlaceOrder mutation (Magento GraphQL) is broken with due to missing State Data

[pmzandbergen]

Original bug report: https://github.com/Adyen/adyen-magento2/issues/1267

The original issue has been closed without providing a (solid) solution. The provided workaround doesn't work in all situations, for example when some kind of Apollo middleware is being used (e.g. Apollo Server). The client / frontend can still bundle the mutations in a single request, but the middleware will use multiple requests to Magento. Since the state data isn't being stored the placeOrder mutation will fail.

The documentation states "use the placeAdyenOrder mutation". It does not mention the placeOrder mutation is broken.

Deviating from standards is sometimes necessary, but is that really the case here? Why is saving the state data, only temporary and encrypted if necessary, an issue?