P: Make folder management more like Windows folder management

When moving a folder from one drive to another, if it is not being dropped into an existing folder, one cannot complete the move within LRC.

In Windows, when performing the same move, one can drop the folder into an empty space at the same nesting level as the existing folders.  That works.

Most other folder/file move operations are identical to Windows folder/file management.  This one should be too.