chore: use file-scoped namespace

src/Shared/HandyControlDemo_Shared/Tools/Helper/Win32Helper.cs

@@ -1,14 +1,13 @@
 using System;
 using System.Runtime.InteropServices;
 
-namespace HandyControlDemo.Tools
-{
-    internal class Win32Helper
-    {
-        [DllImport("user32.dll", ExactSpelling = true, CharSet = CharSet.Auto)]
-        public static extern bool SetForegroundWindow(IntPtr hWnd);
+namespace HandyControlDemo.Tools;
 
-        [DllImport("winmm.dll", EntryPoint = "mciSendString", CharSet = CharSet.Auto)]
-        public static extern int MciSendString(string lpstrCommand, string lpstrReturnString, int uReturnLength, int hwndCallback);
-    }
-}
+internal class Win32Helper
+{
+    [DllImport("user32.dll", ExactSpelling = true, CharSet = CharSet.Auto)]
+    public static extern bool SetForegroundWindow(IntPtr hWnd);
+
+    [DllImport("winmm.dll", EntryPoint = "mciSendString", CharSet = CharSet.Auto)]
+    public static extern int MciSendString(string lpstrCommand, string lpstrReturnString, int uReturnLength, int hwndCallback);
+}