Show .desktop file names based on hidden setting

Implements this. By default .desktop files will show their name property as the file name and not their actual file name in the thunar view.

A listener for GVFS meta data changes has not been implemented (see here for further info). This means the file name of a .desktop file doesn't get updated automatically when somebody marks a .desktop file as secure/unsecure so the user needs to refresh the view of Thunar with F5 manually.