allow orcid_pending to be percolate to the XML graph serialization

dhp-workflows/dhp-graph-provision/src/main/java/eu/dnetlib/dhp/oa/provision/utils/GraphMappingUtils.java

@@ -7,13 +7,15 @@ import java.util.Set;
 
 import com.google.common.collect.Sets;
 
+import eu.dnetlib.dhp.schema.common.ModelConstants;
 import eu.dnetlib.dhp.schema.oaf.*;
 
 public class GraphMappingUtils {
 
 	public static final String SEPARATOR = "_";
 
-	public static Set<String> authorPidTypes = Sets.newHashSet("orcid", "magidentifier");
+	public static Set<String> authorPidTypes = Sets.newHashSet(
+			ModelConstants.ORCID, ModelConstants.ORCID_PENDING, "magidentifier");
 
 	public static String removePrefix(final String s) {
 		if (s.contains("|"))