Simplify the data model to converge towards EDM4hep

• Remove VectorPolar, Direction, FloatPair
• Remove remaining overlapping datatypes in favor of includes from EDM4hep
• Migrate away from using eic::Index in favor of explicit relations
• Rework and simplify the calorimetry data model
• Add utility helpers to streamline usage of EDM4hep vectors and EDM4hep interoperability
• Use get/set syntax consistent with EDM4hep

source/include/eicd/helpers.h

-#ifndef EICD_HELPERS_HH
-#define EICD_HELPERS_HH
-
-
-#include <algorithm>
-#include <cmath>
-#include <exception>
-#include <limits>
-#include <string>
-#include <vector>
-
-#include <Math/Vector4D.h>
-
-#include "eicd/TrackParametersCollection.h"
-#include "eicd/ReconstructedParticleCollection.h"
-#include "eicd/ReconstructedParticleData.h"
-
-namespace eicd::helpers {
-
-  /** Four momentum from track and mass.
-   * Get a vector of 4-momenta from raw tracking info, using an externally
-   * provided particle mass assumption. 
-   */
-  inline auto momenta_from_tracking(const std::vector<eic::TrackParametersData>& tracks,
-                                    const double                                 mass)
-  {
-    std::vector<ROOT::Math::PxPyPzMVector> momenta{tracks.size()};
-    // transform our raw tracker info into proper 4-momenta
-    std::transform(tracks.begin(), tracks.end(), momenta.begin(), [mass](const auto& track) {
-      // make sure we don't divide by zero
-      if (fabs(track.qOverP) < 1e-9) {
-        return ROOT::Math::PxPyPzMVector{};
-      }
-      const double p  = fabs(1. / track.qOverP);
-      const double px = p * cos(track.phi) * sin(track.theta);
-      const double py = p * sin(track.phi) * sin(track.theta);
-      const double pz = p * cos(track.theta);
-      return ROOT::Math::PxPyPzMVector{px, py, pz, mass};
-    });
-    return momenta;
-  }
-} // namespace eicd::helpers
-#endif