Split online.cs and offline.csFile (#941)

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

scripts/dotnet/OfflineModelConfig.cs

@@ -0,0 +1,49 @@
+/// Copyright (c)  2024.5 by 东风破
+
+using System.Linq;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+using System;
+
+namespace SherpaOnnx
+{
+
+    [StructLayout(LayoutKind.Sequential)]
+    public struct OfflineModelConfig
+    {
+        public OfflineModelConfig()
+        {
+            Transducer = new OfflineTransducerModelConfig();
+            Paraformer = new OfflineParaformerModelConfig();
+            NeMoCtc = new OfflineNemoEncDecCtcModelConfig();
+            Whisper = new OfflineWhisperModelConfig();
+            Tdnn = new OfflineTdnnModelConfig();
+            Tokens = "";
+            NumThreads = 1;
+            Debug = 0;
+            Provider = "cpu";
+            ModelType = "";
+        }
+        public OfflineTransducerModelConfig Transducer;
+        public OfflineParaformerModelConfig Paraformer;
+        public OfflineNemoEncDecCtcModelConfig NeMoCtc;
+        public OfflineWhisperModelConfig Whisper;
+        public OfflineTdnnModelConfig Tdnn;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string Tokens;
+
+        public int NumThreads;
+
+        public int Debug;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string Provider;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string ModelType;
+    }
+
+
+}