test(isTaxID): cover dk-DK century digits 5-8 years 37-58

[arronKler]

#2819 already corrected dkDkCheck so century digits 5-8 map years 00-57 to the 2000s and 58-99 to the 1800s (Danish CPR table: https://da.wikipedia.org/wiki/CPR-nummer, also https://blog.ploeh.dk/2018/12/10/danish-cpr-numbers-in-f/). The algorithm change did not add tests for the old 37-58 rejection gap, so #2818 stayed open.

This adds the checksum-valid examples from that issue (0101375005, 0101455009, 0101575004, 0101585018, plus the 36/59 boundaries) to the existing isTaxID dk-DK cases.

Fixes #2818

Checklist

• PR contains only changes related; no stray files, etc.
• README updated (where applicable)
• Tests written (where applicable)
• References provided in PR (where applicable)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (cdb7daf) to head (9838322).

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #2851   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          114       114           
  Lines         2599      2599           
  Branches       658       658           
=========================================
  Hits          2599      2599           

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[arronKler]

Closing this as superseded by #2819, which already landed and closed the algorithm gap for #2818. The extra tests can be revived later if maintainers want them independently.