GtkFileChooserNativeWin32: Add some option flags

GtkFileChooserNativeWin32: Add some option flags

Avoid changing the current directory.
Also avoid creating a sample file to test if the target file
can be created.

References:

* "Why does the common file dialog change the current directory?"
 -> https://devblogs.microsoft.com/oldnewthing/20101112-00/?p=12293

* "Why does the common file save dialog create a temporary file and then delete it?"
 -> https://devblogs.microsoft.com/oldnewthing/20140429-00/?p=1123