Dropped last direct usage of IOHelper in LHCb

Requires lhcb-datapkg/PRConfig!452 (merged) and LHCbIntegrationTests!85 (merged)

It is now only used in the configuration frameworks (LHCbApp and PyConf)

This was done by moving the last tests using it to PyConf (essentially lhcbalgs and Rich ones)

On the way some unused options were dropped, namely LumiMergeFSRConf.py and CheckPGPrimaryVertexPropagation.py