Skip sequencer members from reference comparison

GaudiSequencers print messages of the form

ClassifyClusters     INFO Member list: GaudiSequencer/CaloFutureTrackMatch, LHCb::Calo::Algorithm::ClassifyPhotonElectronAlg/ClassifyPhotonElectron, with context 'Offline'

which are the cause of failing reference comparisons whenever an alogrithm name (or even the C++ type name) changes.

The pro is that they are in a way checking that the python configuration produces the expected data/control flow, at the cost of more painful updates to the control flow. This will be much safer with PyConf so let's get rid of this check here by adding to the preprocessor.

triggered by Rec!1838 (merged)