Update Germany holidays: add th localization, deprecated non-standard ISO code, add subdivision aliases

[PPsyrius]

Proposed change

This PR includes 3 changes for Germany 🇩🇪 holidays:

• Deprecate the unofficial BYP code. Catholic municipalities in Bavaria will instead need to include the CATHOLIC category to mimic the previously implemented behavior.
  • Maybe we can do something similar to Add New Zealand Subdivision Aliases (EN, MI, HASC) #1952 by adding "Bayern (Katholisch)" as a subregion too? I'm open to all suggestions here.
• Add Subdivision Aliases for all Germany subdivisions.
• Add th localization. (Checked with https://bangkok.diplo.de/th-th/botschaft/oeffnungszeiten/1670002 )

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 python-holidays functionality in general)

Checklist

• I've followed the contributing guidelines
• I've run make pre-commit, it didn't generate any changes
• I've run make test, all tests passed locally

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (7ab80ed) to head (7c4cd4a).
Report is 3 commits behind head on dev.

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files          188       188           
  Lines        11403     11407    +4     
  Branches      1789      1790    +1     
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+ Hits         11403     11407    +4     

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[PPsyrius]

Hmm, seems like we might be able to consolidate this a bit further:

[KJhellico]

LGTM.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

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

See analysis details on SonarCloud

[arkid15r]

🇩🇪 LGTM