return instruments in query result where instrument started service or ended service within the time range requested by the user
e.g. request from 2002-01-01T00:00:00 to 2009-01-01T00:00:00 should include RHESSI__HESSI_HXR & RHESSI__HESSI_GMR which started service 2002-02-05T00:00:00
Will be handling this in Release 3;