IFC2x3 and Ifc4 have built in schema validations, through classes implementing `IExpressValidatable`. These validate the standard Express 'Where' rules We need to implement these for IFC4x3 as per https://github.com/xBimTeam/XbimEssentials/commit/4743d909258a2a3e8ee5b2c4b4b77ee815c634a6
