feat(chat): Classes added to chat screen

lib/presentation/chat/chat_screen/models/chat_model.dart

@@ -0,0 +1,16 @@
+// ignore_for_file: must_be_immutable
+
+import 'package:equatable/equatable.dart';
+
+/// This class defines the variables used in the [chat_screen],
+/// and is typically used to hold data that is passed between different parts of the application.
+class ChatModel extends Equatable {
+  ChatModel();
+
+  ChatModel copyWith() {
+    return ChatModel();
+  }
+
+  @override
+  List<Object?> get props => [];
+}