WIP: Proposal to support NAT64

[StarAurryon]

This patch enable IPv6 NAT64 for all the ory products. NAT64 start to become common in Kubernetes IPv6 only clusters.

BREAKING CHANGES: This patch allows by default NAT64 prefixes mirroring the allowed IPv4 prefix in httpx if IPv6 is allowed.

Related Issue or Design Document

No issue created. This is just to talk about the implementation changes with a basic working implementation as reference.

Checklist

• I have read the contributing guidelines and signed the CLA.
• I have referenced an issue containing the design document if my change introduces a new feature.
• I have read the security policy.
• I confirm that this pull request does not address a security vulnerability.
  If this pull request addresses a security vulnerability,
  I confirm that I got approval (please contact [email protected]) from the maintainers to push the changes.
• I have added tests that prove my fix is effective or that my feature works.
• I have added the necessary documentation within the code base (if appropriate).

Further comments