Fix hit sorting problem in MuPatHitTool

MuPatHitTool sorts hits by distance, which can sometimes in the case of S/L overlaps lead to hits from different chambers being interleaved in the hit list. This will cause problems later, as the hit recovery assumes all hits from a given chamber are grouped together. If there are two separate groups of hits from a particular chamber, the hit recovery will run on the chamber twice, each time adding to the track the hits that were not present in the group it's looking at. This fix should prevent this by ensuring that hits from separate chambers are kept separate, thus eliminating the duplicate hit warnings from ATLASRECTS-6396.

Closes ATLASRECTS-6396