Fix: array contains null handling

[Shekharrajak]

Which issue does this PR close?

Closes #3345

Rationale for this change

When array_contains() is called with a literal cast(NULL as array) argument, Comet returns a different result than Spark. Spark follows SQL
three-valued logic where array_contains(NULL, value) should return NULL, but Comet was delegating directly to DataFusion's array_has without proper NULL
array handling.

Other array functions like CometArrayRemove and CometArrayAppend already handle NULL arrays correctly using a CASE WHEN wrapper, but CometArrayContains
was missing this handling.

What changes are included in this PR?

• Added NULL array handling to CometArrayContains in arrays.scala by wrapping the array_has call in a CASE WHEN expression:
  • WHEN array IS NOT NULL THEN array_has(array, key)
  • ELSE NULL
• This follows the same pattern used by CometArrayRemove and CometArrayAppend

How are these changes tested?

Added new test "array_contains - NULL array returns NULL" in CometArrayExpressionSuite

[mbutrovich]

Thanks @Shekharrajak! Can we add/migrate the tests to the new framework?

https://datafusion.apache.org/comet/contributor-guide/sql-file-tests.html

[codecov-commenter]

Codecov Report

❌ Patch coverage is 80.95238% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 60.01%. Comparing base (f09f8af) to head (7cbb557).
⚠️ Report is 920 commits behind head on main.

Files with missing lines	Patch %	Lines
...src/main/scala/org/apache/comet/serde/arrays.scala	80.95%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #3372      +/-   ##
============================================
+ Coverage     56.12%   60.01%   +3.89%     
- Complexity      976     1475     +499     
============================================
  Files           119      175      +56     
  Lines         11743    16185    +4442     
  Branches       2251     2684     +433     
============================================
+ Hits           6591     9714    +3123     
- Misses         4012     5116    +1104     
- Partials       1140     1355     +215     

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[Shekharrajak]

Thanks @Shekharrajak! Can we add/migrate the tests to the new framework?

https://datafusion.apache.org/comet/contributor-guide/sql-file-tests.html

Updated b7929c0

Please trigger the checks .

[andygrove]

Unless this test is testing functionality that isn't already tested in the SQL-based tests, I think we can just remove this.

[andygrove]

LGTM. Thanks @Shekharrajak

[Shekharrajak]

It seems build is failing at create array https://github.com/apache/datafusion-comet/blob/main/spark/src/main/scala/org/apache/comet/serde/arrays.scala#L401

[Shekharrajak]

All checks looks fine now.