Add egammaCalo only extension method. Extrapolate to specific surfaces given by the cluster

Add egammaCalo only extension method. Extrapolate to specific surfaces given by the cluster and find where the track crossed them.

Tag @schaffer , @jdevivi @turra

As an example of possible usage one could change (this actually I confirmed it works but did not change here ) for the rescaled perigee egamma extrapolations in EMExtrapolationTools.cxx

-      std::unique_ptr<Trk::CaloExtension> extension =
-        m_perigeeParticleCaloExtensionTool->caloExtension(
-          ctx, trkPar, direction, Trk::muon);
-      didExtension = extension != nullptr;
-      if (didExtension) {
-        intersections = getIntersections(*extension, cluster);

+      const auto extension =
+        m_perigeeParticleCaloExtensionTool->egammaCaloExtension(
+          ctx, trkPar, cluster,direction);
+      didExtension = !extension.empty();
+      for (const auto& i : extension) {
+        intersections.emplace_back(
+          i.first, i.second->position().eta(), i.second->position().phi());

for now I added the way to do it / method but not something like the above