Add Hangul composition char filter to analysis-nori

[Incheonkirin]

Addresses #16241

Summary

Add an opt-in HangulCompositionCharFilter to analysis-nori. The filter composes modern Hangul conjoining-jamo sequences into precomposed Hangul syllables before KoreanTokenizer, so NFD-form Korean text can analyze like the equivalent NFC text while preserving offset correction back to the original input.

The filter is intentionally narrow: it handles only modern L/V/optional-T conjoining jamo sequences and leaves compatibility jamo, archaic jamo, partial sequences, already-precomposed Korean text, and non-Hangul text unchanged. For general Unicode normalization the ICU module's ICUNormalizer2CharFilter remains the right tool; this covers the common Korean-only case without adding the ICU dependency to nori deployments.

Tests

• NFD Korean sentence through HangulCompositionCharFilter + KoreanTokenizer matches NFC KoreanTokenizer terms/POS
• offsets from analyzed NFD text map back to the original NFD input
• randomized modern Hangul NFD composition matches NFC
• non-modern and partial jamo sequences unchanged
• already-NFC and no-op inputs unchanged
• precomposed-LV + trailing jamo passthrough (out-of-scope shape unchanged)
• factory registration
• bogus factory arguments
• random analyzer data

Verification

• ./gradlew :lucene:analysis:nori:tidy
• ./gradlew :lucene:analysis:nori:check
• ./gradlew check

[rmuir]

the use-case makes sense to me.

constants and formula matches directly with 3.12.3 Hangul Syllable Composition