add main menu interface

- MainMenu
 - ChatItem (Widget)
 - ChatFolder (Widget)
 - ChatFolders (Widget)
 - ColorTheme

client/lib/widgets/chatItem.dart

@@ -0,0 +1,33 @@
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+
+class ChatItem extends StatelessWidget{
+ 
+  ChatItem({super.key,  });
+
+  @override
+  Widget build(BuildContext context) {
+    return SizedBox(
+      width: double.infinity,
+      height: 80,
+      child: TextButton(
+        onPressed: () => print('CHAT'),
+        style: ButtonStyle(
+          backgroundColor: WidgetStatePropertyAll(Theme.of(context).colorScheme.onSecondary),
+          shape: WidgetStatePropertyAll(RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.zero)))
+          ),
+        child: Padding(
+          padding: EdgeInsetsGeometry.all(5),
+          child: Row(
+            children: [
+              Icon(Icons.person, size: 60,),
+              SizedBox(width: 10,),
+              Text('Название', style: TextStyle(fontSize: 18),)
+            ],
+          )
+        )
+      ),
+    );
+  }
+}