Update field.go

Refactored Code Structure: Reorganized the code to use helper functions to reduce complexity and improve readability.
Field Parsing: Removed excessive nesting in the field parsing logic and introduced utility functions for repetitive tasks.
Handling Special Tags: Segregated tag handling into dedicated functions for better maintainability.
Permissions & Default Values: Improved permission setup and default value handling using clear helper methods.
Embedded Fields: Added modular handling for embedded fields, making the code more concise and maintainable.