chore: use file-scoped namespace

src/Shared/HandyControl_Shared/Tools/Converter/Object2StringConverter.cs

@@ -2,15 +2,14 @@
 using System.Globalization;
 using System.Windows.Data;
 
-namespace HandyControl.Tools.Converter
-{
-    public class Object2StringConverter : IValueConverter
-    {
-        public object Convert(object value, Type targetType, object parameter, CultureInfo culture) => value?.ToString();
+namespace HandyControl.Tools.Converter;
 
-        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
-        {
-            throw new NotSupportedException();
-        }
+public class Object2StringConverter : IValueConverter
+{
+    public object Convert(object value, Type targetType, object parameter, CultureInfo culture) => value?.ToString();
+
+    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        throw new NotSupportedException();
     }
-}
+}