Bug-fix / Join Output Orderings

[berkaysynnada]

Which issue does this PR close?

Closes #.

Rationale for this change

Output orderings and ordering equivalence classes of joins may result in suboptimal ways. There are some minor fixes to clean them up.

What changes are included in this PR?

A few util functions are added to normalize orderings and matching sort exprs with columns.

Are these changes tested?

Are there any user-facing changes?

[alamb]

Thank you @berkaysynnada -- this looks like a nice improvement. However, I don't see any tests or test changes in this PR. Can you please add some tests to ensure we don't accidentally break / cause a regression during some future refactor

I also think tests often help to iIllustrate what code is doing

[ozankabak]

LGTM now with the added tests.

Are the existing join operators "advanced" enough to let us write end-to-end SQL tests? If yes, can we add such a test? Otherwise, we can add such a test once we have a join operator that enables us to write such tests.

[alamb]

Are the existing join operators "advanced" enough to let us write end-to-end SQL tests? If yes, can we add such a test? Otherwise, we can add such a test once we have a join operator that enables us to write such tests.

I agree sql level tests would be ideal -- let's try and add them as a follow on PR. I can file a ticket to track this if that is helpful