specialize isEMECIW and isEMECOW methods in LArOnline_SuperCellID (instead of base-class methods)
The Identifier Helper for regular LAr Cells and SuperCells share a common base-class that does most of the job. I found that a few more methods need special implementations for regular cells and supercells: isEMECIW and isEMECOW.
Fixes ATLASRECTS-7971