CLI validation - permit zero or false properties

[markscott-ms]

Description

Whilst testing the Advent of CALM, a property with a false value was created. There are reasonable circumstances where this would be appropriate.

However, there is a spectral rule that raises an error for any empty string, zero number or non-true property anywhere in the architecture.

This PR relaxes the spectral rule to only consider strings, i.e. properties with the value "".

• Properties with a zero value are now permitted, e.g. { "metadata" : { "minimum-instances": 0 } }
• Properties with a false value are now permitted, e.g. { "metadata" : { "data-encrypted-at-rest": false } }

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update
• 🎨 Code style/formatting changes
• ♻️ Refactoring (no functional changes)
• ⚡ Performance improvements
• ✅ Test additions or updates
• 🔧 Chore (maintenance, dependencies, CI, etc.)

Affected Components

• CLI (cli/)
• Shared (shared/)
• CALM Widgets (calm-widgets/)
• CALM Hub (calm-hub/)
• CALM Hub UI (calm-hub-ui/)
• Documentation (docs/)
• VS Code Extension (calm-plugins/vscode/)
• Dependencies
• CI/CD

Commit Message Format ✅

Testing

• I have tested my changes locally
• I have added/updated unit tests
• All existing tests pass

Checklist

• My commits follow the conventional commit format
• I have updated documentation if necessary
• I have added tests for my changes (if applicable)
• My changes follow the project's coding standards

[markscott-ms]

This PR will remain in draft as I highly suspect a merge conflict will be caused when #1872 is merged as similar lines have been modified.