EKS: Support metadata IMDSv2

[christoph-beckmann-tm]

User Story
As EKS user
I wanna enable IMDSv2 for my launch templates
so that my EC2 instance running without IMDSv1

Full backgrund can be seen here:
https://aws.amazon.com/blogs/security/get-the-full-benefits-of-imdsv2-and-disable-imdsv1-across-your-aws-infrastructure/

AC

• EC2 instance run with IMDSv2 enable

[christoph-beckmann-tm]

I found metadata_options:
https://github.com/kbst/terraform-kubestack/blob/master/aws/cluster/configuration.tf#L33

      metadata_options_http_endpoint               = "enabled"
      metadata_options_http_tokens                 = "required"
      metadata_options_http_put_response_hop_limit = 1

I guess its just missing in the documentation:
https://www.kubestack.com/framework/documentation/clusters/#configuration