implemented in-chat search with text highlighting, added search navigation UI, and integrated scrollable list for message jumping

lib/view/pages/talk/data/chat_message.dart

@@ -1,12 +1,12 @@
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter_linkify/flutter_linkify.dart';
 
 import '../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
 import '../../../../model/account_data.dart';
 import '../../../../model/endpoint_data.dart';
 import '../../../../utils/url_opener.dart';
+import '../widgets/highlighted_linkify.dart';
 
 class ChatMessage {
   String originalMessage;
@@ -27,8 +27,13 @@ class ChatMessage {
     );
   }
 
-  Widget getWidget() {
-    var contentWidget = Linkify(text: content, onOpen: UrlOpener.onOpen);
+  Widget getWidget({String? highlightQuery, TextStyle? style}) {
+    var contentWidget = HighlightedLinkify(
+      text: content,
+      onOpen: UrlOpener.onOpen,
+      highlight: highlightQuery,
+      style: style,
+    );
 
     if (originalData?['object']?.type == RichObjectStringObjectType.talkPoll) {
       return ListTile(