Fix shopperIP

[MarioNaise]

Summary

Fix shopperIP field in makePaymentRequest and createSessionRequest objects:
Currently, payment.controller.js unconditionally sets the shopperIP field on paymentObject to the value from the requests x-forwarded-for header and then applies it to the initial request object later on.
This means that any shopperIP provided by the initial request gets lost.
Additionally, the x-forwarded-for header contains a wrong value (most likely the Commercetools server IP), so it should not be used as a fallback at all.
Instead, if shopperIP is missing in the clients request, it should just stay undefined.

Tested scenarios

• makePaymentRequest contains shopperIP -> shopperIP will be forwarded to Adyen
• makePaymentRequest doesn't contain shopperIP ->shopperIP stays undefined
• createSessionRequest contains shopperIP -> shopperIP will be forwarded to Adyen
• createSessionRequest doesn't contain shopperIP -> shopperIP stays undefined

Fixed issue:

[andihalberkamp]

Hi @merijndebeer-adyen ,

A colleague has provided a fix for the issue described above. This is an important issue for us because it prevents the correct IP address from being sent to Adyen.

As a result, the 3D Secure popup is shown to customers more frequently than necessary, which could negatively impact our conversion rate.

It would be great if you could review the PR when you have a moment. If you have any questions, please feel free to contact me or @MarioNaise.