MuonR4 - Introduce mapping function between symmetric matrices & vectors

• Helper functions to establish a bijective mapping between the elements of a NxN matrix A with A_{ij} = A_{ji} and a linear vector
• Keep track which tube layer is the first from the second multilayer
• Hit sorting before creating the segment.

MuonSpectrometer/MuonPhaseII/MuonPatternRecognition/MuonPatternRecognitionAlgs/src/SegmentFittingAlg.cxx

@@ -276,6 +276,7 @@ namespace MuonR4 {
         genCfg.hitPullCut = m_seedHitChi2;
         genCfg.recalibSeedCircles = m_recalibSeed;
         genCfg.fastSeedFit = m_refineSeed;
+        genCfg.fastSegFitWithT0 = m_doT0Fit;
         genCfg.calibrator = m_calibTool.get();
         
 
@@ -352,7 +353,8 @@ namespace MuonR4 {
         
         /** If no degree of freedom is in the segment fit then try to plug the holes  */
         if (data.nDoF<=0 || data.calibMeasurements.empty()) {
-            ATH_MSG_VERBOSE("No degree of freedom available. What shall be removed?!");
+            ATH_MSG_VERBOSE("No degree of freedom available. What shall be removed?!. nDoF: "
+                            <<data.nDoF<<", n-meas: "<<data.calibMeasurements);
             return false;
         }
 
@@ -541,6 +543,10 @@ namespace MuonR4 {
                                                 }
                                                 return true;
                                                 }), candidate.calibMeasurements.end());
+
+        std::ranges::sort(candidate.calibMeasurements, [](const Segment::MeasType& a, const Segment::MeasType& b){
+            return a->positionInChamber().z() < b->positionInChamber().z();
+        });
         const MuonGMR4::SpectrometerSector* chamber{nullptr};
         for (const auto& hit : candidate.calibMeasurements) {
             if (hit->type() != xAOD::UncalibMeasType::Other){