Added FileSizeNameConverter

Toolkit.UI.Avalonia/BooleanToPasswordCharConverter.cs

@@ -18,4 +18,4 @@ public class BooleanToPasswordCharConverter :
 
     public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) =>
         throw new NotImplementedException();
-}
+}

Toolkit.UI.Avalonia/FileSizeNameConverter.cs

@@ -0,0 +1,37 @@
+using Avalonia.Data.Converters;
+using Avalonia.Markup.Xaml;
+using System.Globalization;
+
+namespace Toolkit.UI.Avalonia;
+
+public class FileSizeNameConverter : 
+    MarkupExtension,
+    IValueConverter
+{
+    public override object ProvideValue(IServiceProvider serviceProvider) =>
+        this;
+
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is long fileSize)
+        {
+            string[] sizeSuffixes = ["bytes", "KB", "MB", "GB", "TB", "PB"];
+
+            int order = 0;
+            double adjustedSize = fileSize;
+
+            while (adjustedSize >= 1024 && order < sizeSuffixes.Length - 1)
+            {
+                order++;
+                adjustedSize /= 1024;
+            }
+
+            return $"{adjustedSize:0.##} {sizeSuffixes[order]}";
+        }
+
+        return "0 bytes";
+    }
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture) => 
+        throw new NotImplementedException();
+}