[SPARK-36124][SQL][WIP] Support subqueries with correlation through set operators

[jchen5]

What changes were proposed in this pull request?

Adds support for subquery decorrelation with UNION, INTERSECT, and EXCEPT on the correlation paths. For example:

SELECT t1a, (
  SELECT sum(b) FROM (
    SELECT t2b as b FROM t2 WHERE t2a = t1.t1a
    INTERSECT
    SELECT t3b as b FROM t3 WHERE t3a = t1.t1a
))
FROM t1

Why are the changes needed?

To improve subquery support in Spark.

Does this PR introduce any user-facing change?

Before this change, queries like this would return an error like: Decorrelate inner query through Union is not supported.

After this PR, this query can run successfully.

How was this patch tested?

Unit tests and (WIP) SQL query tests.

[jchen5]

@allisonwang-db @cloud-fan

[AmplabJenkins]

Can one of the admins verify this patch?

[jchen5]

This rewrite still needs some work, I found that it is not introducing DomainJoins properly, working on a fix for that.

[jchen5]

Created a new PR here: #39375