Add SSH keys for NodeGroups

[JeremyGibson]

As an administrator, when there are problems that traditional logging isn't capturing it might be helpful to be able to ssh into the nodes.

Relevant documentation:
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-eks-nodegroup-remoteaccess.html

AC:

• Add a RemoteAccess parameter to the eks.Nodegroup

• Add RemoteAccess with key pair to bastion security