TESTERS WANTED: RyuLDN implementation (#65)

These changes allow players to matchmake for local wireless using a LDN
server. The network implementation originates from Berry's public TCP
RyuLDN fork. Logo and unrelated changes have been removed.

Additionally displays LDN game status in the game selection window when
RyuLDN is enabled.

Functionality is only enabled while network mode is set to "RyuLDN" in
the settings.

src/Ryujinx/UI/Helpers/MultiplayerInfoConverter.cs

@@ -0,0 +1,44 @@
+using Avalonia.Data.Converters;
+using Avalonia.Markup.Xaml;
+using Ryujinx.Ava.Common.Locale;
+using Ryujinx.UI.App.Common;
+using Ryujinx.UI.Common.Helper;
+using System;
+using System.Globalization;
+
+namespace Ryujinx.Ava.UI.Helpers
+{
+    internal class MultiplayerInfoConverter : MarkupExtension, IValueConverter
+    {
+        private static readonly MultiplayerInfoConverter _instance = new();
+
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is ApplicationData applicationData)
+            {
+                if (applicationData.PlayerCount != 0 && applicationData.GameCount != 0)
+                {
+                    return $"Hosted Games: {applicationData.GameCount}\nOnline Players: {applicationData.PlayerCount}";
+                }
+                else
+                {
+                    return "";
+                }
+            }
+            else
+            {
+                return "";
+            }
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotSupportedException();
+        }
+
+        public override object ProvideValue(IServiceProvider serviceProvider)
+        {
+            return _instance;
+        }
+    }
+}