Add referencing existing security groups for inbound traffic

[changhyuni]

Issue

#2688

Description

Enable more flexible management of security groups, I add a security group source chaining feature to inbound security groups. This is great for allowing traffic from public IP spaces, but for internal ALBs, it would be ideal to allow inbound traffic from specific security groups. For instance, allowing API Gateway traffic (via VPC Link) to an ALB without exposing the ALB to the entire subnet or VPC. It would be preferable to reference the security group of the VPC Link. Similarly, you might want to allow a specific EC2 instance (not part of the EKS cluster) to connect to an ALB while restricting access for another EC2 instance.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the docs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: changhyuni / name: loanshark (1e57960)

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @changhyuni. Thanks for your PR.

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: changhyuni
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[shraddhabang]

/ok-to-test

[changhyuni]

@shraddhabang Hi.
Could you take a look at the PR when you have time?