Fix NPE in ArrayListRowsAndColumns when intermediate column is not found

[sreemanamala]

Description

In ArrayListRowsAndColumns when we try to access an intermediate column which is not part of signature, we get an NPE

example query failing due to this:

select cityName, array_concat_agg(ARRAY[cityName], 10000) over (PARTITION BY cityName) as c
from wikipedia
where countryName='Austria'
group by cityName

---

Key changed/added classes in this PR

• ArrayListRowsAndColumns

---

This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.