NUIApp constructor
      
      NUIApp({ 
    
    
- required BuildType buildType,
- required String title,
- required NUIFutureRoute homeScreen,
- Map<String, NUIRoute> ? routes,
- String? initialRoute,
- RouteFactory? onGenerateRoute,
- ThemeDataInflaterFunction? themeDataDefault,
- required OverlayInflaterFunction? overlayStyle,
- required NUIRoute loadingScreen,
- AsyncFunction? preAppTask,
Implementation
NUIApp({
  required this.buildType,
  required this.title,
  required this.homeScreen,
  this.routes,
  this.initialRoute,
  // required this.themeData,
  this.onGenerateRoute,
  this.themeDataDefault,
  required this.overlayStyle,
  required this.loadingScreen,
  this.preAppTask
}){
  _appBuildType = buildType;
}