feat: Add support for wafv2 ack

[arditti]

What does this PR do?

This PR adds support for the AWS WAFv2 ACK (AWS Controllers for Kubernetes) controller to the terraform-aws-eks-ack-addons module. It includes:

• Addition of WAFv2 controller configuration
• Required IAM permissions and policies
• Helm chart configurations
• Documentation updates for WAFv2 controller usage

Motivation

• Resolves issue #80
• Enables users to manage WAFv2 resources directly from their Kubernetes clusters using ACK

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• [] Yes, I ran pre-commit run -a with this PR

For Moderators

• E2E Test successfully complete before merge?

Additional Notes

Testing performed:

1. Ran ./tests/complete/README.md guidance
2. Created sample WAFv2 web ACL using ACK controller
3. Verified WAFv2 resources created in AWS console
4. Tested resource deletion and cleanup

Controller version tested: v1.0.6

Terraform version: 1.11.3