Three small muon reconstruction fixes

Apologies for blending three fixes into a single MR, but each involve small changes to a single file:

1. CSC and NSW hits are only written out now if the corresponding detectors are actually used
2. The MuonCombinedInDetExtensionAlg was using obsolete names for the NSW PRD containers
3. The sorting of calo and MS hits in the SortTSOSs method was exactly backwards.