Deprecation of sak-kubernetes module

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What would you like to be added:
Deprecate sak-kubernetes module with using aws-eks-terraform module.
https://github.com/terraform-aws-modules/terraform-aws-eks

Why is this needed:`.
There is no need to support custom solution. Better to simply use aws-eks-terraform, this module became common module for deploying eks cluster with terraform.

We can leave sak-kubernetes repo in working state and change all examples to use new module.

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Also migration to new module should go smooth for new and old infrastructures.