added a swipeable media gallery for chat and folder images and videos with server previews, on-demand originals and zoom, and marked document previews in chat so they no longer pass for photos

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

@@ -1,12 +1,10 @@
-import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/material.dart';
 
 import '../../../../api/marianumcloud/talk/chat/get_chat_response.dart';
 import '../../../../api/marianumcloud/talk/chat/rich_object_string_processor.dart';
-import '../../../../model/endpoint_data.dart';
-import '../../../../session/session_manager.dart';
 import '../../../../utils/emoji_detection.dart';
 import '../../../../utils/url_opener.dart';
+import '../widgets/chat_file_attachment.dart';
 import '../widgets/highlighted_linkify.dart';
 import '../widgets/message_markdown.dart';
 
@@ -78,36 +76,7 @@ class ChatMessage {
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
-          CachedNetworkImage(
-            errorWidget: (context, url, error) => Row(
-              mainAxisSize: MainAxisSize.min,
-              crossAxisAlignment: CrossAxisAlignment.center,
-              children: [
-                const Icon(Icons.file_open_outlined, size: 35),
-                const SizedBox(width: 10),
-                Flexible(
-                  child: Text(
-                    file.name,
-                    maxLines: 2,
-                    overflow: TextOverflow.ellipsis,
-                    style: const TextStyle(fontWeight: FontWeight.bold),
-                  ),
-                ),
-                const SizedBox(width: 10),
-              ],
-            ),
-            alignment: Alignment.center,
-            placeholder: (context, url) => const Padding(
-              padding: EdgeInsets.all(15),
-              child: SizedBox(width: 50, child: LinearProgressIndicator()),
-            ),
-            fadeInDuration: Duration.zero,
-            fadeOutDuration: Duration.zero,
-            errorListener: (value) {},
-            httpHeaders: SessionManager().requireNextcloud().authHeaders,
-            imageUrl:
-                '${EndpointData().nextcloud().origin()}/index.php/core/preview?fileId=${file.id}&x=130&y=-1&a=1',
-          ),
+          ChatFileAttachment(file: file),
           if (originalMessage != '{file}') ...[
             SizedBox(height: 5),
             contentWidget,