CAKE-114 | applied disclaimer page when user install wallet first time; applied route to disclaimer page as initial route (main.dart); change leading widget in the disclaimer page; applied call of welcome page when user press accept button in the disclaimer page

lib/view_model/settings/settings_view_model.dart

@@ -144,7 +144,7 @@ abstract class SettingsViewModelBase with Store {
         RegularListItem(
           title: S.current.settings_terms_and_conditions,
           handler: (BuildContext context) =>
-              Navigator.of(context).pushNamed(Routes.disclaimer),
+              Navigator.of(context).pushNamed(Routes.readDisclaimer),
         ),
         RegularListItem(
           title: S.current.faq,