feat(lbn): Add Lebanon national ID validator

[AngusHsu]

Description

Add support for Lebanon National ID.

Parent Epic

#14 - Add support for new countries

Lebanon National ID Format

• Research needed on exact format
• May include registry and sequence numbers

Tasks

• Research and verify format
• Create src/countries/lbn/ directory
• Implement NationalId validator class
• Implement validate() with checksum (if any)
• Implement parse() function
• Add to main dispatcher
• Add to getCountryIdFormat()
• Write comprehensive tests (80%+ coverage)

Acceptance Criteria

• Validation works correctly
• Format documented
• Test coverage 80%+

Labels

enhancement, new-country, lebanon