Fix MuonIdHelperTool initialisation for ATLASSIM-4263

Hi, this MR should fix https://its.cern.ch/jira/browse/ATLASSIM-4263 by letting MuonIdHelperTool decide to not use CSC/MM/sTGC if the corresponding helpers cannot be found. Also a WARNING message is printed that users should steer this behaviour via the properties of the MuonIdHelperTool in the future to get rid of the WARNING. Adding @jchapman who might be interested in this. Best, Nico