MuonNswSegmentMaker - Improve the IP constraint & revise the Pad association

Hi everybody,

this MR makes use of the distanceToPad function - introduced in !65692 (merged) - to associate the best sTgc pads to the muon segments. Further, the checks to assess whether a micromega segment seed is viable is improved. Thus far, dR constraints were imposed on 2 parallel strips, but not on the ones having a stereo angle to each other. The improved method takes the left & right strip edges and compares their dR. If both edges exceed the minimum or maximum dR threshold, the seed building for all following strips in the layer is aborted and a new combination is tried.

Tagging: @pscholer