Show how to implement AWS KMS in customer template

Need to enhance documentation and terraform on AWS KMS use.

• Show how user would add/remove permissions to KMS keys for administrator and user (read-only)
• Show how user would update key values in KMS.
• Show how user would update .sops with ARN and re-encrypt secrets
• Create terraform to automatically create IAM role/policy and attach to RKE2 agent
• Create terraform to automatically create a SOPS key in KMS and update .sops.yaml
• Add documentation on settings in IAM role/policy required