fix(routing): settings page routing

Before this commit the Settings Page was not considered as a route,
instead all the content of the page was replacing the content below,
since the `_notTransitionPageRoute()` method was used to "push" the
route.

After this commit to push the route the `_cupertinoPageRoute()` method
is being used. With that edit the Settings Page is treated like a normal
route, and so it's possible to swipe back and navigate correctly to the
route.

Closes: RIP-Comm#218

lib/routes.dart

@@ -61,7 +61,7 @@ Route<dynamic> makeRoute(RouteSettings settings) {
     case '/graphs':
       return _materialPageRoute(settings.name, const GraphsPage());
     case '/settings':
-      return _noTransitionPageRoute(settings.name, const SettingsPage());
+      return _cupertinoPageRoute(settings.name, const SettingsPage());
     case '/general-settings':
       return _cupertinoPageRoute(settings.name, const GeneralSettingsPage());
     case '/notifications-settings':
@@ -90,14 +90,3 @@ PageRoute _materialPageRoute(String? routeName, Widget viewToShow) {
     builder: (_) => viewToShow,
   );
 }
-
-PageRoute _noTransitionPageRoute(String? routeName, Widget viewToShow) {
-  return PageRouteBuilder(
-    transitionDuration: const Duration(),
-    reverseTransitionDuration: const Duration(),
-    settings: RouteSettings(
-      name: routeName,
-    ),
-    pageBuilder: (_, __, ___) => viewToShow,
-  );
-}