Klay -> Kaia in license

[ian0371]

Proposed changes

This pr adds a script update-license-kaia.go. It categorizes existing licenses into seven categories: kaia, klaytn, mixed, ethereum, go, any, none.

• kaia is to filter already applied files.
• klaytn, mixed: adds kaia authors.
• none: adds kaia authors. Some files that have ambiguous licenses are left as-is.
• others: left as-is.

LICENSE_TYPE=1 go run build/update-license-kaia.go # Klaytn
LICENSE_TYPE=2 go run build/update-license-kaia.go # Mixed
LICENSE_TYPE=6 go run build/update-license-kaia.go # None
# then manaully edit None files

Types of changes

• Bugfix
• New feature or enhancement
• Others

Checklist

• I have read the CONTRIBUTING GUIDELINES doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes ($ make test)
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules