cli: warn when untested node version

[davidjgoss]

🤔 What's changed?

Distinguish between supported (error if not met) and tested (warning if not met) Node.js versions.

⚡️ What's your motivation?

See #1958 (comment)

🏷️ What kind of change is this?

• 🏦 Refactoring/debt/DX (improvement to code design, tooling, docuemntation etc. without changing behaviour)

📋 Checklist:

• I agree to respect and uphold the Cucumber Community Code of Conduct
• I've changed the behaviour of the code
  • I have added/updated tests to cover my changes.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• Users should know about my change
  • I have added an entry to the "Unreleased" section of the CHANGELOG, linking to this pull request.

[coveralls]

Coverage increased (+0.002%) to 98.221% when pulling 772c7e0 on feat/node-warn-untested into 8e53bab on main.