Fixed dependency with win32_registry and add Friendly name option

[dickverweij]

This pull request updates the Windows implementation of protocol handler registration to support specifying a friendly application name, and also updates a dependency for compatibility and improvements.

Protocol registration improvements:

• The register method in ProtocolHandlerWindows now accepts an optional friendlyAppName parameter. If provided, the application name is registered under the protocol's registry key, allowing Windows to display a user-friendly name for the handler.

Dependency updates:

• The win32_registry dependency has been updated from version ^1.0.2 to ^2.1.0 in pubspec.yaml to ensure compatibility with recent changes and improvements in the package.