Make the "AbstractOpenAireProfile" return a serializable ValidationResult.

src/main/java/eu/dnetlib/validator2/validation/guideline/openaire/AbstractOpenAireProfile.java

@@ -37,7 +37,7 @@ public abstract class AbstractOpenAireProfile implements XMLApplicationProfile,
     }
 
     @Override
-    public ValidationResult validate(String id, Document document) {
+    public StandardValidationResult validate(String id, Document document) {
         int maxScore = maxScore();
         double score = 0;
         final Map<String, Guideline.Result> results = new HashMap<>();