Create random durations with positive nanoseconds

Previously, test code that generated random durations could create a
duration with negative amount of nanoseconds. Such duration is now
normalized by the database so that nanoseconds value is always in
range from 0 to 999_999_999.

This commit makes tests only create random durations with nanoseconds
in that range. Otherwise some test assertions fail because they expect
non-normalized value to be returned back.

Author: lutovich

driver/src/test/java/org/neo4j/driver/v1/util/TemporalUtil.java

@@ -81,7 +81,7 @@ public static ZonedDateTime randomZonedDateTimeWithZoneId()
     public static IsoDuration randomDuration()
     {
         int sign = random().nextBoolean() ? 1 : -1; // duration can be negative
-        return new InternalIsoDuration( sign * randomInt(), sign * randomInt(), sign * randomInt(), sign * Math.abs( random( NANO_OF_SECOND ) ) );
+        return new InternalIsoDuration( sign * randomInt(), sign * randomInt(), sign * randomInt(), Math.abs( random( NANO_OF_SECOND ) ) );
     }
 
     private static ZonedDateTime randomZonedDateTime( ZoneId zoneId )