Add function to print the volume

GeoModelCore/GeoModelHelpers/GeoModelHelpers/printVolume.h

+/*
+  Copyright (C) 2002-2025 CERN for the benefit of the ATLAS collaboration
+*/
+#ifndef GEOMODELUTILS_PRINTVOLUME_H
+#define GEOMODELUTILS_PRINTVOLUME_H
+#include "GeoModelKernel/GeoVPhysVol.h"
+
+/** @brief creates a string to print the volume */
+std::string printVolume(const PVConstLink& volume);
+
+#endif
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