feat(sample-app): Migrate sample app to v4

Signed-off-by: xsahil03x <[email protected]>

packages/stream_chat_v1/lib/channel_page.dart

@@ -60,7 +60,7 @@ class _ChannelPageState extends State<ChannelPage> {
   Widget build(BuildContext context) {
     return Scaffold(
       backgroundColor: StreamChatTheme.of(context).colorTheme.appBg,
-      appBar: ChannelHeader(
+      appBar: StreamChannelHeader(
         showTypingIndicator: false,
         onImageTap: () async {
           var channel = StreamChannel.of(context).channel;
@@ -108,7 +108,7 @@ class _ChannelPageState extends State<ChannelPage> {
           Expanded(
             child: Stack(
               children: <Widget>[
-                MessageListView(
+                StreamMessageListView(
                   initialScrollIndex: widget.initialScrollIndex,
                   initialAlignment: widget.initialAlignment,
                   highlightInitialMessage: widget.highlightInitialMessage,
@@ -137,7 +137,7 @@ class _ChannelPageState extends State<ChannelPage> {
                         );
                       },
                       deletedBottomRowBuilder: (context, message) {
-                        return const VisibleFootnote();
+                        return const StreamVisibleFootnote();
                       },
                     );
                   },
@@ -155,8 +155,7 @@ class _ChannelPageState extends State<ChannelPage> {
                         .colorTheme
                         .appBg
                         .withOpacity(.9),
-                    child: TypingIndicator(
-                      alignment: Alignment.centerLeft,
+                    child: StreamTypingIndicator(
                       padding: const EdgeInsets.symmetric(
                         horizontal: 8,
                         vertical: 4,
@@ -174,7 +173,7 @@ class _ChannelPageState extends State<ChannelPage> {
               ],
             ),
           ),
-          MessageInput(
+          StreamMessageInput(
             focusNode: _focusNode,
             messageInputController: _messageInputController,
           ),