Menus finally working again in v2 designer upgrade branch

[tznind]

Finally got MenuBar working correctly again after all the changes to PopoverMenu etc.

See the draft update branch for v2: gui-cs/TerminalGuiDesigner#320

The latest stable v2 branch of Terminal.Gui that works with designer is still 4538. The new PR will update to latest beta (5211+).

Generates code like

//------------------------------------------------------------------------------

//  <auto-generated>
//      This code was generated by:
//        TerminalGuiDesigner v2.0.0.0
//      Changes to this file may cause incorrect behavior and will be lost if
//      the code is regenerated.
//  </auto-generated>
// -----------------------------------------------------------------------------
namespace YourNamespace {
    using System;
    using Terminal.Gui;
    using Terminal.Gui.App;
    using Terminal.Gui.Drawing;
    using Terminal.Gui.Input;
    using Terminal.Gui.ViewBase;
    using Terminal.Gui.Views;
    using System.Collections;
    using System.Collections.Generic;
    using System.Collections.ObjectModel;
    using System.Drawing;
    
    
    public partial class MyView : Terminal.Gui.Views.Dialog {
        
        private Terminal.Gui.Views.MenuBar menuBar;
        
        private Terminal.Gui.Views.MenuBarItem fileMenu;
        
        private Terminal.Gui.Views.MenuItem editMeMenuItem;
        
        private Terminal.Gui.Views.MenuItem newMenuItem;
        
        private Terminal.Gui.Views.MenuItem carMenuItem;
        
        private Terminal.Gui.Views.MenuItem bycicleMenuItem;
        
        private Terminal.Gui.Views.MenuItem pramMenuItem;
        
        private Terminal.Gui.Views.MenuItem otherMenuItem;
        
        private Terminal.Gui.Views.MenuItem hoolaHoopMenuItem;
        
        private Terminal.Gui.Views.MenuItem skateboardMenuItem;
        
        private Terminal.Gui.Views.MenuItem helloMenuItem;
        
        private Terminal.Gui.Views.MenuItem thereMenuItem;
        
        private void InitializeComponent() {
            this.menuBar = new Terminal.Gui.Views.MenuBar();
            this.Width = Dim.Percent(90);
            this.Height = Dim.Percent(80);
            this.X = Pos.Center();
            this.Y = Pos.Center();
            this.Visible = true;
            this.Arrangement = Terminal.Gui.ViewBase.ViewArrangement.Overlapped;
            this.CanFocus = true;
            this.ShadowStyle = Terminal.Gui.ViewBase.ShadowStyles.Transparent;
            this.TextAlignment = Terminal.Gui.ViewBase.Alignment.Start;
            this.menuBar.Width = Dim.Fill(0);
            this.menuBar.Height = Dim.Auto();
            this.menuBar.X = 0;
            this.menuBar.Y = 0;
            this.menuBar.Visible = true;
            this.menuBar.Arrangement = Terminal.Gui.ViewBase.ViewArrangement.Fixed;
            this.menuBar.CanFocus = false;
            this.menuBar.ShadowStyle = Terminal.Gui.ViewBase.ShadowStyles.Transparent;
            this.menuBar.Data = "menuBar";
            this.menuBar.TextAlignment = Terminal.Gui.ViewBase.Alignment.Start;
            this.fileMenu = new Terminal.Gui.Views.MenuBarItem();
            this.fileMenu.Title = "_File";
            this.fileMenu.Key = Key.F9;
            this.editMeMenuItem = new Terminal.Gui.Views.MenuItem();
            this.editMeMenuItem.Title = "Edit Me";
            this.newMenuItem = new Terminal.Gui.Views.MenuItem();
            this.newMenuItem.Title = "New";
            this.carMenuItem = new Terminal.Gui.Views.MenuItem();
            this.carMenuItem.Title = "Car";
            this.bycicleMenuItem = new Terminal.Gui.Views.MenuItem();
            this.bycicleMenuItem.Title = "Bycicle";
            this.pramMenuItem = new Terminal.Gui.Views.MenuItem();
            this.pramMenuItem.Title = "Pram";
            this.otherMenuItem = new Terminal.Gui.Views.MenuItem();
            this.otherMenuItem.Title = "Other";
            this.hoolaHoopMenuItem = new Terminal.Gui.Views.MenuItem();
            this.hoolaHoopMenuItem.Title = "Hoola hoop";
            this.skateboardMenuItem = new Terminal.Gui.Views.MenuItem();
            this.skateboardMenuItem.Title = "Skateboard";
            this.otherMenuItem.SubMenu = new Menu([hoolaHoopMenuItem,skateboardMenuItem]);
            this.newMenuItem.SubMenu = new Menu([carMenuItem,bycicleMenuItem,pramMenuItem,otherMenuItem]);
            this.helloMenuItem = new Terminal.Gui.Views.MenuItem();
            this.helloMenuItem.Title = "Hello";
            this.thereMenuItem = new Terminal.Gui.Views.MenuItem();
            this.thereMenuItem.Title = "There";
            this.fileMenu.PopoverMenu = new PopoverMenu([editMeMenuItem,newMenuItem,helloMenuItem,thereMenuItem]);
            this.menuBar.Add(this.fileMenu);
            this.Add(this.menuBar);
        }
    }
}