refactor: remove deprecated approute

lib/components/image_bubble.dart

@@ -1,5 +1,4 @@
 import 'package:famedlysdk/famedlysdk.dart';
-import 'package:fluffychat/utils/app_route.dart';
 import 'package:fluffychat/views/image_view.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/foundation.dart';
@@ -235,8 +234,8 @@ class _ImageBubbleState extends State<ImageBubble> {
         onTap: () {
           if (!widget.tapToView) return;
           Navigator.of(context).push(
-            AppRoute(
-              ImageView(widget.event, onLoaded: () {
+            MaterialPageRoute(
+              builder: (_) => ImageView(widget.event, onLoaded: () {
                 // If the original file didn't load yet, we want to do that now.
                 // This is so that the original file displays after going on the image viewer,
                 // waiting for it to load, and then hitting back. This ensures that we always

lib/utils/app_route.dart

@@ -1,35 +0,0 @@
-import 'package:adaptive_page_layout/adaptive_page_layout.dart';
-import 'package:flutter/cupertino.dart';
-import 'package:flutter/material.dart';
-
-class AppRoute extends PageRouteBuilder {
-  static Route defaultRoute(BuildContext context, Widget page) {
-    return context != null &&
-            !AdaptivePageLayout.of(context).columnMode(context)
-        ? CupertinoPageRoute(
-            builder: (BuildContext context) => page,
-          )
-        : AppRoute(page);
-  }
-
-  final Widget page;
-  AppRoute(this.page)
-      : super(
-          pageBuilder: (
-            BuildContext context,
-            Animation<double> animation,
-            Animation<double> secondaryAnimation,
-          ) =>
-              page,
-          transitionsBuilder: (
-            BuildContext context,
-            Animation<double> animation,
-            Animation<double> secondaryAnimation,
-            Widget child,
-          ) =>
-              FadeTransition(
-            opacity: animation,
-            child: child,
-          ),
-        );
-}

lib/utils/event_extension.dart

@@ -4,7 +4,6 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_cache_manager/flutter_cache_manager.dart';
 import 'matrix_file_extension.dart';
-import 'app_route.dart';
 import '../views/image_view.dart';
 
 extension LocalizedBody on Event {
@@ -12,9 +11,7 @@ extension LocalizedBody on Event {
     if (!downloadOnly &&
         [MessageTypes.Image, MessageTypes.Sticker].contains(messageType)) {
       await Navigator.of(context).push(
-        AppRoute(
-          ImageView(this),
-        ),
+        MaterialPageRoute(builder: (_) => ImageView(this)),
       );
       return;
     }