crypto: deduplicate X509 subject matching logic

[tniessen]

CheckHost(), CheckEmail(), and CheckIP() all do very similar things. Extract the common logic into a helper function CheckX509Subject() to avoid duplication.

[nodejs-github-bot]

Review requested:

• @nodejs/crypto

[codecov]

Codecov Report

❌ Patch coverage is 88.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.33%. Comparing base (79def6d) to head (0f3664c).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/crypto/crypto_x509.cc	88.00%	0 Missing and 3 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #63644   +/-   ##
=======================================
  Coverage   90.32%   90.33%           
=======================================
  Files         732      732           
  Lines      236435   236428    -7     
  Branches    44527    44520    -7     
=======================================
+ Hits       213563   213577   +14     
  Misses      14589    14589           
+ Partials     8283     8262   -21     

Files with missing lines	Coverage Δ
src/crypto/crypto_x509.cc	73.63% <88.00%> (+1.18%)	⬆️

... and 42 files with indirect coverage changes

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[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/73829/