Refactor C# code and support building nuget packages for cross-platforms (#144)

scripts/dotnet/run.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+# Copyright (c)  2023  Xiaomi Corporation
+
+set -ex
+
+mkdir -p macos linux windows all
+
+cp ./online.cs all
+cp ./offline.cs all
+
+./generate.py
+
+pushd linux
+dotnet build -c Release
+dotnet pack -c Release -o ../packages
+popd
+
+pushd macos
+dotnet build -c Release
+dotnet pack -c Release -o ../packages
+popd
+
+pushd windows
+dotnet build -c Release
+dotnet pack -c Release -o ../packages
+popd
+
+pushd all
+dotnet build -c Release
+dotnet pack -c Release -o ../packages
+popd
+
+ls -lh packages