Flix sample application should have a base ViewModel class.

[andrew-carmichael]

Is your feature request related to a problem? Please describe. In order to add new screens to the Flix sample application, a developer will have to create a view model with some boiler plate code. This boiler plate could be eliminated with a ViewModel base class.

This feedback relates to:

• [ ] The Kotlin library
• [ ] The Gradle plugin
• [ ] The IntelliJ Platform plugin
• [X ] The sample code
• [ ] The documentation

Describe the solution you'd like A base ViewModel class so that we don't have to duplicate the exposed properties each time a ViewModel is created.

Describe alternatives you've considered

Additional context