fix: Check CSE name aliases for collisions.

[ritchie46]

Trust, but verify.

fixes #16138

[codecov]

Codecov Report

Attention: Patch coverage is 96.47059% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 80.94%. Comparing base (b2291b9) to head (f180bdd).

❗ Current head f180bdd differs from pull request most recent head 416c477. Consider uploading reports for the commit 416c477 to get more accurate results

Files	Patch %	Lines
...rs-plan/src/logical_plan/optimizer/cse/cse_expr.rs	96.05%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #16149      +/-   ##
==========================================
- Coverage   80.96%   80.94%   -0.02%     
==========================================
  Files        1386     1386              
  Lines      178492   178409      -83     
  Branches     2882     2882              
==========================================
- Hits       144508   144416      -92     
- Misses      33492    33502      +10     
+ Partials      492      491       -1     

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