Align financial markets MIC codes with ISO 10383

[KJhellico]

Proposed change

Align financial markets MIC codes with ISO 10383 (NYSE → XNYS, ECB → XECB).
Add consistency test for financial markets table in README.rst.

Type of change

• New country/market holidays support (thank you!)
• Supported country/market holidays update (calendar discrepancy fix, localization)
• Existing code/documentation/test/process quality improvement (best practice, cleanup, refactoring, optimization)
• Dependency update (version deprecation/pin/upgrade)
• Bugfix (non-breaking change which fixes an issue)
• Breaking change (a code change causing existing functionality to break)
• New feature (new holidays functionality in general)

Checklist

• I've followed the contributing guidelines
• I've successfully run make check, all checks and tests are green

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (e969609) to head (d28eb1c).
Report is 2 commits behind head on dev.

Additional details and impacted files

@@            Coverage Diff            @@
##               dev     #2158   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          194       194           
  Lines        11557     11559    +2     
  Branches      1641      1641           
=========================================
+ Hits         11557     11559    +2     

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[arkid15r]

LGTM

[arkid15r]

Just for the record -- I've already implemented this change as a part of our v1 standardization goal here. Thanks for adding it to v0 too!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud