feat: copy linkBg theme property in message theme.

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

packages/stream_chat_flutter/lib/src/quoted_message_widget.dart

@@ -281,7 +281,7 @@ class QuotedMessageWidget extends StatelessWidget {
 
   Color? _getBackgroundColor(BuildContext context) {
     if (_containsLinkAttachment) {
-      return StreamChatTheme.of(context).colorTheme.linkBg;
+      return messageTheme.linkBackgroundColor;
     }
     return messageTheme.messageBackgroundColor;
   }