* Specifies which pool to join for the user-data/cloud-init script to pick up
* Allows both name and ARN based instance profiles to be specified
* Properly encodes user-data as base64
* Passes in credentials in constructor for easier testing (e.g read credentials from default $HOME/.aws location)
* Upgrade of NuGet packages required to get the new InstanceMetadataOptionsRequest
#preflight 62f3cb4db43215cf6c283946
[CL 21319081 by carl bystrom in ue5-main branch]