Expose `FindData` struct

Expose `FindData` struct: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-win32_find_dataa

```C
typedef struct _WIN32_FIND_DATAW {
DWORD dwFileAttributes;
FILETIME ftCreationTime;
FILETIME ftLastAccessTime;
FILETIME ftLastWriteTime;
DWORD nFileSizeHigh;
DWORD nFileSizeLow;
DWORD dwReserved0;
DWORD dwReserved1;
WCHAR cFileName[MAX_PATH];
WCHAR cAlternateFileName[14];
DWORD dwFileType; // Obsolete. Do not use.
DWORD dwCreatorType; // Obsolete. Do not use
WORD wFinderFlags; // Obsolete. Do not use
} WIN32_FIND_DATAW, *PWIN32_FIND_DATAW, *LPWIN32_FIND_DATAW;
```

Otherwise it's hard to determine file-type efficiently when using `findFirstFile`/`findNextFile`: https://hackage.haskell.org/package/Win32-2.13.2.0/docs/System-Win32-File.html#v:findFirstFile