VLC_HOME_DIR doesn't point to the right folder on Windows

Refs. #29488

VLC_HOME_DIR is documented as the "User's home". On UNIX systems that would be ~. On Windows that should be %USERPROFILE% which is environment variable available even on Windows XP.

But it was coded to point to CSIDL_PERSONAL which is %USERPROFILE%/Documents.

This is a problem for things like sftp which is looking for .ssh in VLC_HOME_DIR.

However there are other uses that rely on the existing location like the Lua home directory that some scripts may rely on.

To mimick what already existed, the UAP/UWP version of VLC_HOME_DIR also points to the documents folder.