Implement a cleanup function for MockDirUACBypass

[matterpreter]

When a user deletes the mock directory C:\Windows \System32\, Windows will attempt to delete the real System32. Need to implement a cleanup function to do this as an argument. This can likely be done with kernel32!RemoveDirectory, but will require a few other steps as the directory must be emptied prior to deletion.

[matterpreter]

Addressed in d82b26e but needs further testing