HHH-16035 change the default for hibernate.type.preferred_duration_jdbc_type to NUMERIC

There's really no value at all in having h2 as the only platform where Duration
is persisted as 'interval second' by default. People usually use h2 for testing,
and probably actually prefer if the schema is more similar to the schema of
their "real" database.

Also, this tiny change fixes issues 1. and 2. of HHH-16035 as a side-effect.

hibernate-core/src/main/java/org/hibernate/internal/util/config/ConfigurationHelper.java

@@ -546,7 +546,7 @@ public final class ConfigurationHelper {
 			return explicitSetting;
 		}
 
-		return SqlTypes.INTERVAL_SECOND;
+		return SqlTypes.NUMERIC;
 	}
 
 	@Incubating