feat: Add support for AL2023 `nodeadm` user data

[bryantbiggs]

Description

• Add support for AL2023 nodeadm user data

Motivation and Context

• Ref https://github.com/awslabs/amazon-eks-ami/issues/1678

Breaking Changes

• No

How Has This Been Tested?

• [x] I have updated at least one of the examples/* to demonstrate and validate my change(s)
• [x] I have tested and validated these changes using one or more of the provided examples/* projects
• [x] I have executed pre-commit run -a on my pull request

ToDo

• [x] Remove pre and post bootstrap fields from AL2023 templates - this isn't valid/warranted with MIME multi-part
• [x] Add example nodegroup for both EKS and self-managed nodegroup
• [ ] Validate GA API