Add view file to SIP arrangement

refs #6131

Add two download files to filesystem_ajax: one that proxies to the
storage service, another which reads from local disk. Update view file
to use the storage servie, update browse AIP to use the local FS.
Update archival storage to use storage service helpers, so the base
storage service URL is only fetched in one place.
Remove unused transfer browser

Early attempt at SIP arrangement, superseded by existing SIP
arrangement.
Moving files from storage service more generic

Create_sip function in replaced by more generic copy_files to fetch files
from the storage service.  Added a helper to fetch files from backlog.