Added in-app fileviewer for images and pdf files

lib/view/pages/talk/chatBubble.dart

@@ -235,7 +235,7 @@ class _ChatBubbleState extends State<ChatBubble> {
         }
 
         downloadProgress = 1;
-        downloadCore = FileElement.download(message.file!.path!, message.file!.name, (progress) {
+        downloadCore = FileElement.download(context, message.file!.path!, message.file!.name, (progress) {
           if(progress > 1) {
             setState(() {
               downloadProgress = progress;