fix: Change edm4hep track state writing to write params (#1311)

The current implementation tries to use the projector on the track parameters. This changes that.

Also, we need to consider what we actually write here. In principle we can do perigees relative to the surface center.

Examples/Io/EDM4hep/src/EDM4hepUtil.cpp

@@ -272,17 +272,20 @@ void EDM4hepUtil::writeTrajectory(
       return true;
     }
 
-    Acts::BoundVector meas = state.projector().transpose() * state.parameters();
-    Acts::BoundMatrix cov =
-        state.projector() * state.covariance() * state.projector().transpose();
+    Acts::BoundVector params = state.parameters();
+    Acts::BoundMatrix cov = state.covariance();
 
     edm4hep::TrackState trackState;
 
-    trackState.D0 = meas[Acts::eBoundLoc0];
-    trackState.Z0 = meas[Acts::eBoundLoc1];
-    trackState.phi = meas[Acts::eBoundPhi];
-    trackState.tanLambda = std::tan(M_PI_2 - meas[Acts::eBoundTheta]);
-    trackState.omega = meas[Acts::eBoundQOverP];  // TODO convert
+    // @FIXME: Using D0/Z0 to store local 0/local 1
+    // For proper d0/z0 we'd have to propagate to the perigee here or convert to
+    // perigee relative to surface center, but it's also not really what we want
+    // to store anyway
+    trackState.D0 = params[Acts::eBoundLoc0];
+    trackState.Z0 = params[Acts::eBoundLoc1];
+    trackState.phi = params[Acts::eBoundPhi];
+    trackState.tanLambda = std::tan(M_PI_2 - params[Acts::eBoundTheta]);
+    trackState.omega = params[Acts::eBoundQOverP];  // TODO convert
     trackState.referencePoint = {0, 0, 0};
 
     // TODO apply jacobian to covariance