[Feature]: Foreign Exchange API

[leonidasv]

Feature summary

Add support for the Foreign Exchange API

Problem statement

The current SDK does not have support for the Foreign Exchange API: https://docs.adyen.com/api-explorer/foreignexchange/1/post/rates/calculate

Proposed solution

I'd like to ask the Adyen team to implement the Foreign Exchange API, mirroring the current Adyen API documentation.

Alternatives considered

No response

Additional context

No response