feat: Add cilium to Kubernetes addon

[florentio]

What does this PR do?

Closes #439

Cilium can be set up in two different manners in EKS cluster:

Cilium in combination with the Amazon VPC CNI plugin

Cilium can be deployed in combination with the Amazon VPC CNI plugin by enabling the add-on via the following values.

cni:
  chainingMode: aws-cni
tunnel: disabled
enableIPv4Masquerade: false

Cilium as a replacement of Amazon VPC CNI

If you aim to install cilium as a [replacement of Amazon VPC CNI] (https://docs.cilium.io/en/stable/gettingstarted/k8s-install-helm/) for default CNI in your cluster, below is the configuration.

eni:
  enabled: true
ipam:
  mode: eni
tunnel: disabled
egressMasqueradeInterfaces: eth0
nodeinit:
  enabled: true
hubble:
  relay:
      enabled: true
   ui:
      enabled: true

Full values file is here https://github.com/cilium/cilium/blob/master/install/kubernetes/cilium/values.yaml

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• Yes, I have added a new example under examples to support my PR
• Yes, I have created another PR for add-ons under add-ons repo (if applicable)
• Yes, I have updated the docs for this feature
• Yes, I ran pre-commit run -a with this PR

Note: Not all the PRs required examples and docs except a new pattern or add-on added.

For Moderators

• E2E Test successfully complete before merge?

Additional Notes

[bryantbiggs]

Thank you!