Associate ssh key pair to dataplane node to help debug

[hakuna-matatah]

Issue #, if available:

Description of changes:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[mengqiy]

LGTM.
Thanks for preparing the change. This will help us troubleshooting node problem when SSM can't be used.

[mengqiy]

asgs: 1

An error occurred (InvalidKeyPair.NotFound) when calling the DescribeKeyPairs operation: The key pair 'scaletest-us-west-2-nodegroups-ssh-key' does not exist
KeyPair already exists
sh: out of range

An error occurred (InvalidParameterException) when calling the CreateNodegroup operation: Remote access configuration cannot be specified with a launch template.

It seems we can't specify launch template and remote access at the same time.
https://tekton.scalability.eks.aws.dev/#/namespaces/scalability/pipelineruns/awscli-eks-load-5k-v131-slos-t6mln-r-s6g99?pipelineTask=create-mng-monitoring-nodes&step=create-nodegroup