fix: Code style consistency

[redaranj]

Changes in this pull request

• Improve documentation formatting consistency
• Break multi-class files into separate files
• Refactor JSON handling
• Code consistency improvements

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• All applicable changes have been documented
• Any TO DO items (or similar) have been entered as GitHub issues and the link to that issue has been included in a comment

[codecov]

Codecov Report

❌ Patch coverage is 67.08861% with 26 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.99%. Comparing base (600c62a) to head (93635a3).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
Library/Sources/C2PAJson.swift	48.27%	15 Missing ⚠️
Library/Sources/C2PAError.swift	66.66%	10 Missing ⚠️
Library/Sources/Builder.swift	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #76      +/-   ##
==========================================
- Coverage   77.53%   76.99%   -0.54%     
==========================================
  Files          39       42       +3     
  Lines        1291     1313      +22     
==========================================
+ Hits         1001     1011      +10     
- Misses        290      302      +12     

Flag	Coverage Δ
unittests	76.99% <67.08%> (-0.54%)	⬇️

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