Add enhancement proposal for NAP WAF integration

[ciarams87]

Proposed changes

Write a clear and concise description that helps reviewers understand the purpose and impact of your changes. Use the
following format:

Problem: As a maintainer of NGF
I want a design to describe what the UX and high level implementation details I need for WAF v5
So that I can implement that design later to build the feature in NGF.

Solution: Create an enhancement proposal detailing the architecture of the proposed design. Note this does not go into any code specific implementation details or design, this proposal is focused on the overall architecture and approach.

Testing: Deployed the multi-container NGINX pod with NAP WAF installed as detailed in the proposal, and ensured WAF protection was running against the traffic. I have not tested any of the Policy pulling mechanisms detailed in the proposal.

Please focus on (optional): If you any specific areas where you would like reviewers to focus their attention or provide
specific feedback, add them here.

Closes #3341

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

If this PR introduces a change that affects users and needs to be mentioned in the release notes,
please add a brief note that summarizes the change.

[salonichf5]

Great work Ciara 🚀