SwiftFacility module Observation handling

[phycodurus]

The SwiftFacility does not yet handle the Observations that result from the creating a TOO request.
Desirable features:

• List previous Swift Observations of this target (with filter on requester, etc)
• Show requested and planned ToO requests, their status, and if scheduled, when.
• Make sure UVOT filter list is up-to-date with cannonical list from Swift web pages
• Total Exposure Time in form should automatically be (visits * exposure time/visit)
• If UVOT, then set XRT Mode to Auto

see also #43