fix(golang): correctly map nullable PostgreSQL UUID[] columns

[nerocorp935]

Closes #1
/claim #1

Summary

• Corrects type generation logic for nullable PostgreSQL UUID[] array columns.
• Maps nullable array columns to pointer slice representations (*[]uuid.UUID) when using standard database/sql drivers or when pointer types are configured.
• Preserves standard non-nullable slice mapping ([]uuid.UUID) for UUID[] NOT NULL columns.
• Adds comprehensive unit tests under internal/codegen/golang/types_test.go covering driver settings and nullability variations.