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.