Avalonia - Save Manager (#3476)

* Add save manager to account selector

* add fallback to app metadata for titlename if app is not in gamelist

* Allow recovering lost accounts

Ryujinx.Ava/Ui/Windows/MainWindow.axaml.cs

@@ -36,6 +36,7 @@ namespace Ryujinx.Ava.Ui.Windows
 {
     public partial class MainWindow : StyleableWindow
     {
+        internal static MainWindowViewModel MainWindowViewModel { get; private set; }
         private bool _canUpdate;
         private bool _isClosing;
         private bool _isLoading;
@@ -81,6 +82,8 @@ namespace Ryujinx.Ava.Ui.Windows
         {
             ViewModel = new MainWindowViewModel(this);
 
+            MainWindowViewModel = ViewModel;
+
             DataContext = ViewModel;
 
             InitializeComponent();