Refactor .Net example project (#1049)

Co-authored-by: 东风破 <birdfishs@163.com>

scripts/dotnet/OnlineRecognizerResult.cs

@@ -1,15 +1,13 @@
-/// Copyright (c)  2023  Xiaomi Corporation (authors: Fangjun Kuang)
+/// Copyright (c)  2023  Xiaomi Corporation (authors: Fangjun Kuang)
 /// Copyright (c)  2023 by manyeyes
 /// Copyright (c)  2024.5 by 东风破
-
-using System.Collections.Generic;
-using System.Linq;
+using System;
 using System.Runtime.InteropServices;
 using System.Text;
-using System;
 
 namespace SherpaOnnx
 {
+
     public class OnlineRecognizerResult
     {
         public OnlineRecognizerResult(IntPtr handle)