Properly implemented vsg::getDirectoryContents on the Windows platform

[appcodegen]

Description

This change uses the FindFirstFileW/FindNextFileW API function pair (with correct parameters) instead of FindFirstFileNameW/FindNextFileNameW (which only enumerates hard links and was using invalid parameters)

Fixes #905

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

I tested this locally using a modified 'vsgviewer' example as there doesn't seem to be an example dedicated to Path/Paths/Filesystem classes/functions.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules