[Go] Refactor Go serialization code structure for maintainability

[chaokunyang]

Feature Request

No response

Is your feature request related to a problem? Please describe

The current codebase has:

• Mixed responsibilities in single files
• Unclear separation between serializers and core logic
• Difficulty finding and understanding code paths
• Some inconsistent naming conventions

Describe the solution you'd like

Reorganize the codebase:

• Separate reader and writer logic into dedicated files (reader.go, writer.go)
• Extract type-specific serializers (array, primitive, pointer, time, etc.)
• Rename files for clarity (resolver.go → meta_string_resolver.go)
• Group related types and constants
• Improve code documentation

Benefits

• Easier code navigation and maintenance
• Clear separation of concerns
• Better discoverability of functionality
• Reduced file sizes and complexity

Describe alternatives you've considered

No response

Additional context

#2982