[SPARK-55794][SQL] Always alias OuterReferences

[mihailotim-db]

What changes were proposed in this pull request?

In this PR I propose that we always alias OuterReferences

Why are the changes needed?

These changes are needed for 2 main reasons: provide avoid potential issues with exposing raw outer references and their expressions ids and provide compatibility between fixed-point and single-pass analyzers.

For example, in a query like:

table t
|> where exists (
    table other
    |> extend t.x
    |> select * except (a, b))

before this change, the output will be:

Filter exists#x [x#1]
:  +- Project [x#1]
:     +- Project [a#3, b#4, outer(x#1)]
:        +- SubqueryAlias spark_catalog.default.other
:           +- Relation spark_catalog.default.other[a#3,b#4] json
+- PipeOperator
   +- SubqueryAlias spark_catalog.default.t
      +- Relation spark_catalog.default.t[x#1,y#2] csv

The output of the subquery is now exactly the same as the one from outer reference (x#1). This can potentially cause query failures or correctness issues, but at the moment only presents as a compatibility issue between fixed-point and single-pass analyzers

Does this PR introduce any user-facing change?

No

How was this patch tested?

Added new test cases + existing tests

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

No

[dtenedor]

Looks good, thanks for making the behavior converge between the analyzers.

[dtenedor]

LGTM, merging to master