[SPARK-52311][SQL] Fix bug with multiple self-references with UnresolvedSubqueries in rCTEs

[Pajaraja]

What changes were proposed in this pull request?

Change the way the output is handled in the case where we give the names of the columns in the rCTE as a SubqueryAlias is handled. Now we make sure that anchor gives the correct names by pushing the UnresolvedSubqueryColumnAlias into it, and also make sure that the UnionLoopRef has this output as well.

Why are the changes needed?

Currently rCTEs don't behave properly in case when the anchor references the same column multiple times in the anchor, leading to wrong things being identified in the recursion.
For example this rCTE:

WITH RECURSIVE tmp(x) AS (
values (1), (2), (3), (4), (5)
), rcte(x, y) AS (
SELECT x, x FROM tmp WHERE x = 1
UNION ALL
SELECT x + 1, x FROM rcte WHERE x < 5
)
SELECT * FROM rcte;

Will return:

1 1
2 2
3 3
4 4
5 5

Instead of:

1 1
2 1
3 2
4 3
5 4

Does this PR introduce any user-facing change?

No.

How was this patch tested?

New tests in cte-recursion.sql golden file.

Was this patch authored or co-authored using generative AI tooling?

No.