3.0.0 Update to Dart 3 and dependencies

• Update minimum Dart version to 3.0.0.
• Update dependencies.

2.1.0 - nadgrids

• Nadgrids support

2.0.0 - nullsafe version

• Stable null safety release.
• BREAKING CHANGE: Projection('key') syntax is no longer available since factory constructors cannot return null value use Projection.get('key') instead.