Support create cluster default addon metrics-server

[gustavodiaz7722]

Description

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the userdocs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes
• (Core team) Added labels for change area (e.g. area/nodegroup) and kind (e.g. kind/improvement)

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 🌟

[gustavodiaz7722]

Manually tested using following procedure

1. create cluster using eksctl default addonseksctl create cluster
2. Verify metrics-server created on cluster using aws cli aws eks list-addons --cluster-name
3. Verify metrics-server becomes active on cluster using aws cli aws eks describe-addon --addon-name metrics-server --cluster-name

[jhcook]

This merge is not documented and has broken our deployments. Thanks.

https://eksctl.io/usage/addons/