Fix code style on MaterialDesignThemes.Wpf.Internal files

Author: L1nstead

src/MaterialDesignThemes.Wpf/Internal/TreeListViewItemsCollection.cs

@@ -6,8 +6,8 @@ namespace MaterialDesignThemes.Wpf.Internal;
 
 public class TreeListViewItemsCollection : ObservableCollection<object?>
 {
-    private List<int> ItemLevels { get; } = new();
-    private List<bool> ItemIsExpanded { get; } = new();
+    private List<int> ItemLevels { get; } = [];
+    private List<bool> ItemIsExpanded { get; } = [];
 
     public TreeListViewItemsCollection(object? wrappedSource)
     {
@@ -319,14 +319,8 @@ public static void MoveItem(this IList list, int oldIndex, int newIndex)
     }
 }
 
-public class MoveEventArgs : EventArgs
+public class MoveEventArgs(int oldIndex, int newIndex) : EventArgs
 {
-    public int OldIndex { get; }
-    public int NewIndex { get; }
-
-    public MoveEventArgs(int oldIndex, int newIndex)
-    {
-        OldIndex = oldIndex;
-        NewIndex = newIndex;
-    }
+    public int OldIndex { get; } = oldIndex;
+    public int NewIndex { get; } = newIndex;
 }