Missing CMakeLists.txt for Win32

[ilyapas]

The directory ports/win32/vs_2019 is missing a CMakeLists.txt file. It is required for CMake-based builds of FileX on Windows platform, as CMake calls add_subdirectory() command on that directory. The same file as in ports/linux/gnu could be used for ports/win32/vs_2019 as well, since the folder structure is the same.