Windows visit Chinese filename not found

[qicosmos]

download a file with Chinese filename by static file server, will return not found on Windows, Linux is ok.

http://127.0.0.1:9001/中文测试.txt 

[osabc]

~~urldecode 后，相关path文件操作不要用 std::string 类型而是用 std::filesystem::path 就可以了~~

[qicosmos]

噢？有代码吗？

[qicosmos]

或者你提个pr？

[osabc]

#667