[core] Refactor NullFalseLeafFunction

[Zouxxyy]

Purpose

• Currently In and NotIn predicate are null false, this PR extract a common parent class NullFalseLeafFunction for them
• fix when all stats is null, equal(0, null) still should be false

Tests

• All original UT passed
• New case

PredicateBuilder builder = new PredicateBuilder(RowType.of(new IntType()));
Predicate predicate = builder.equal(0, null);
// new
assertThat(test(predicate, 1, new FieldStats[] {new FieldStats(null, null, null)})).isEqualTo(false);

API and Format

Documentation

[JingsongLi]

I think this is a good improvement, but this code is very prone to bugs, so we don't need to refactor it when there are no requirements.

[Zouxxyy]

close it currently