feat(cubesql): SET ROLE changes authentication context

[MazterQyou]

Check List

• Tests have been run in packages where changes made if available
• Linter has been run for changed code
• Tests for the changes have been added if not covered yet
• Docs have been added / updated if required

Description of Changes Made

This PR makes SET ROLE statement, in addition to updating the role variable, change the authentication context accordingly. Related tests are included.

[codecov]

Codecov Report

❌ Patch coverage is 92.85714% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 84.66%. Comparing base (9243f4c) to head (10f704b).
⚠️ Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
rust/cubesql/cubesql/src/compile/router.rs	87.09%	8 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #9982   +/-   ##
=======================================
  Coverage   84.66%   84.66%           
=======================================
  Files         254      254           
  Lines       90271    90329   +58     
=======================================
+ Hits        76427    76478   +51     
- Misses      13844    13851    +7     

Flag	Coverage Δ
cubesql	84.66% <92.85%> (+<0.01%)	⬆️

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[KSDaemon]

👍🏻 LGTM!