Refs #9349 - Move monitor det ID check to validator.
Refs #9349 - Make changes to CalculateTransmission algorithm ...

... to allow for a region of interest to be used for the transmission
rather than a monitor.
Refs #9349 - Have trans ROI var as well as monitor.

Get rid of the mess to do with the property, getter and setter.  It was
uncessary.
Refs #9349 - Add code to extract spectra from a ws.

Includes addition to the SANSUtility unit tests, which apparently were
never being run as the file was not listed in CMakeList.txt.
Refs #9349 - CalcTrans reduction step now accepts ROI.
Refs #9349 - Utility to extract masked detector IDs.
Refs #9349 - Utility to get all detector IDs in a component.
Refs #9349 - Fully support "beam stop out" commands.

Everything should be in place now.
Merge branch 'feature/9349_extend_trans_command_to_allow_beam_stop_out' into develop