Validate region name from S3 redirect

[hssyoo]

Uses the existing validate_region_name utility to validate new region name when redirecting.

[codecov-commenter]

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.61%. Comparing base (b0a4fbe) to head (e291c50).
⚠️ Report is 338 commits behind head on develop.
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Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3644      +/-   ##
===========================================
- Coverage    92.71%   92.61%   -0.11%     
===========================================
  Files           68       68              
  Lines        15561    15631      +70     
===========================================
+ Hits         14428    14477      +49     
- Misses        1133     1154      +21     

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