Add encryption and obfuscation utilities for sensitive data

[mitchelllisle]

Extend the library with utilities for encryption and obfuscation of sensitive data fields. Consider support for:

• Configurable encryption algorithms (e.g., AES, RSA)
• Tokenization or hashing for obfuscation
• Easy integration with Spark workflows
• Documentation and examples for using these utilities

This will help teams ensure that sensitive or regulated data is protected both at rest and in transit.