Make moving files more generic

refs #6248

Add functions to move files/folders to and from the storage service.
Moving to the storage service from the original location deposits them
in a staging area associated with the destination Space.  Moving from
the storage service to the final destination moves the file from the
destination Space's staging area to the destination path.  The staging
area is locally accessible to the storage service, which makes the move
to/from storage service functions much simpler than trying to move to
any protocol space.

Each protocol space implements these functions, and the parent Space
calls them as needed.  Several protocol spaces have similar
requirements, so helper functions were placed in the Space class for
moving locally (using os.rename) and rsync.

Update store_aip to use the new functions.
Staging path in default Space

refs #6248

Add staging path to default Space.  Only set the default transfer
source and AIP storage paths if they're unset.