feature: UI: LDN Games Viewer

This window can be accessed via "Help" menu in the title bar.
This menu's data is synced with the in-app-list LDN game data, and that has been modified to hide unjoinable games (in-progress and/or private (needing a passphrase)). You can still see these games in the list.

src/Ryujinx/UI/Windows/LdnGamesListWindow.axaml.cs

@@ -0,0 +1,79 @@
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+using Gommon;
+using Ryujinx.Ava.Common.Locale;
+using Ryujinx.Ava.Systems.Configuration;
+using Ryujinx.Ava.UI.Helpers;
+using Ryujinx.Ava.UI.ViewModels;
+using Ryujinx.Common;
+using Ryujinx.Common.Helper;
+using System.Threading.Tasks;
+
+namespace Ryujinx.Ava.UI.Windows
+{
+    public partial class LdnGamesListWindow : StyleableAppWindow
+    {
+        public static async Task Show(string searchTerm = null)
+        {
+            using LdnGamesListViewModel ldnGamesListVm = new(RyujinxApp.MainWindow.ViewModel);
+
+            await ShowAsync(new LdnGamesListWindow
+            {
+                DataContext = ldnGamesListVm,
+                SearchBoxFlush = { Text = searchTerm ?? string.Empty },
+                SearchBoxNormal = { Text = searchTerm ?? string.Empty }
+            });
+        }
+
+        public LdnGamesListWindow() : base(useCustomTitleBar: true, 37)
+        {
+            Title = RyujinxApp.FormatTitle(LocaleKeys.LdnGameListTitle);
+
+            InitializeComponent();
+
+            FlushControls.IsVisible = !ConfigurationState.Instance.ShowOldUI;
+            NormalControls.IsVisible = ConfigurationState.Instance.ShowOldUI;
+
+            RefreshFlush.Command = RefreshNormal.Command =
+                Commands.Create(() => (DataContext as LdnGamesListViewModel)?.RefreshAsync().OrCompleted());
+
+            InfoFlush.Command = InfoNormal.Command = 
+                Commands.Create(() => OpenHelper.OpenUrl(SharedConstants.MultiplayerWikiUrl));
+        }
+
+        // ReSharper disable once UnusedMember.Local
+        // its referenced in the axaml but rider keeps yelling at me that its unused so
+        private void TextBox_OnTextChanged(object sender, TextChangedEventArgs e)
+        {
+            if (DataContext is not LdnGamesListViewModel cvm)
+                return;
+
+            if (sender is not TextBox searchBox)
+                return;
+
+            cvm.Search(searchBox.Text);
+        }
+
+        public void Sort_Name_Checked(object sender, RoutedEventArgs args)
+        {
+            if (sender is RadioButton { Tag: string sortStrategy })
+            {
+                if (DataContext is not LdnGamesListViewModel cvm)
+                    return;
+
+                cvm.NameSorting(int.Parse(sortStrategy));
+            }
+        }
+
+        public void Sort_PlayerCount_Checked(object sender, RoutedEventArgs args)
+        {
+            if (sender is RadioButton { Tag: string sortStrategy })
+            {
+                if (DataContext is not LdnGamesListViewModel cvm)
+                    return;
+
+                cvm.StatusSorting(int.Parse(sortStrategy));
+            }
+        }
+    }
+}