OZP-69: Define domain models.
> OZP-273: Perform code review

1. Added Range validator for WidgetDefinition height and width validation.
2. Moved Email and Range validator testing to DescribeEntityValidationAnnotationProcessor.groovy.
3. Added error message tests for Range and Email validators as well.
Entity WidgetDefinition has a factory method for creating Intent Value Objects and Intents can only be created through this factory