updated project linter-rules and enforced them

lib/view/pages/talk/chatDetails/chatInfo.dart

@@ -66,7 +66,7 @@ class _ChatInfoState extends State<ChatInfo> {
             if(participants != null) ...[
               ListTile(
                 leading: const Icon(Icons.supervised_user_circle),
-                title: Text("${participants!.data.length} Teilnehmer"),
+                title: Text('${participants!.data.length} Teilnehmer'),
                 trailing: const Icon(Icons.arrow_right),
                 onTap: () => TalkNavigator.pushSplitView(context, ParticipantsListView(participants!)),
               ),

lib/view/pages/talk/chatDetails/participants/participantsListView.dart

@@ -16,7 +16,7 @@ class _ParticipantsListViewState extends State<ParticipantsListView> {
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
-        title: const Text("Teilnehmende"),
+        title: const Text('Teilnehmende'),
       ),
       body: ListView(
         children: widget.participantsResponse.data.map((participant) {