Restructure unhandled buttons

lib/screen/pages/talk/chatList.dart

@@ -5,6 +5,7 @@ import 'package:jiffy/jiffy.dart';
 import 'package:marianum_mobile/api/marianumcloud/talk/chat/richObjectStringProcessor.dart';
 import 'package:marianum_mobile/api/marianumcloud/talk/room/getRoomResponse.dart';
 import 'package:marianum_mobile/data/chatList/chatListProps.dart';
+import 'package:marianum_mobile/widget/unimplementedDialog.dart';
 import 'package:persistent_bottom_nav_bar/persistent_tab_view.dart';
 import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
@@ -43,7 +44,9 @@ class _ChatListState extends State<ChatList> {
         actions: [
           IconButton(
             icon: const Icon(Icons.search),
-            onPressed: () => {},
+            onPressed: () => {
+              UnimplementedDialog.show(context)
+            },
           )
         ],
       ),

lib/screen/pages/timetable/appointmentDetails.dart

@@ -9,6 +9,7 @@ import 'package:syncfusion_flutter_calendar/calendar.dart';
 
 import '../../../api/webuntis/queries/getRooms/getRoomsResponse.dart';
 import '../../../api/webuntis/queries/getSubjects/getSubjectsResponse.dart';
+import '../../../widget/unimplementedDialog.dart';
 import '../../settings/debug/jsonViewer.dart';
 import '../more/roomplan/roomplan.dart';
 
@@ -64,7 +65,7 @@ class AppointmentDetails {
                 trailing: IconButton(
                   icon: const Icon(Icons.textsms_outlined),
                   onPressed: () {
-                    showDialog(context: context, builder: (context) => const AlertDialog(content: Text("Not implemented yet")));
+                    UnimplementedDialog.show(context);
                   },
                 ),
               ),

lib/widget/unimplementedDialog.dart

@@ -0,0 +1,8 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+
+class UnimplementedDialog {
+  static void show(BuildContext context) {
+    showDialog(context: context, builder: (context) => const AlertDialog(content: Text("Not implemented yet")));
+  }
+}