fix: Cannot start application when code page is 65001. Closes #814.

This commit may cause breaking change: changing working directory to the directory where the executable locates in.

HMCLauncher/HMCL/os.h

@@ -16,7 +16,7 @@ LSTATUS MyGetModuleFileName(HMODULE hModule, std::wstring &out);
 LSTATUS MyGetEnvironmentVariable(LPCWSTR name, std::wstring &out);
 
 // Create process by invoking CreateProcess, only pass command.
-bool MyCreateProcess(const std::wstring &command);
+bool MyCreateProcess(const std::wstring &command, const std::wstring& workdir);
 
 // Check if file lpPath exists.
 bool FindFirstFileExists(LPCWSTR lpPath, DWORD dwFilter);