Cloudwatch legacy clean-up

[cpyle0819]

• Update or add Readmes based on current templates
• Confirm code works as intended
• Add to SoS and update snippets to current standards
• Update code comments
• Fully lint code
• Delete useless or duplicate code and ensure there are no external links to it
• Create and/or fix tests as required

[github-actions]

Marked stale by the Shirriff. Notifying @aws-sdk-docs-code-maintainers.