The MuonFixedId from the muon calibration framework is very useful to define an identifier exportable outside the athena world. (The MuonFixedId is also used in the muon alignment code)
However, the MuonFixedId packs the detector-specific values in a 32-bit payload, using a set of rules that do not leave enough space for the new muon detector technologies MM and sTGC.
This MR introduces a MuonFixedLongId that uses a 64-bit payload, allowing for the new muon detectors. The logic (for the old detector technologies) is identical to that of MuonFixedId, with slightly more space allowed in the packing for each of the detector-specific values.
The validity of the proposed packing is checked using an atlas_test in MuonSpectrometer/MuonCalib/MuonCalibIdentifier/test/MuonFixedLongId_test.cxx
This MR was created on request of @jojungge so that the proposed changes can be reviewed.