Improve LM configuration serialization and deserialization for CoSTORM

[JamesHWade]

This PR enhances the serialization and deserialization of language model configurations in the CoStormRunner class. It improves persistence by properly saving and restoring LM configurations and introduces proper handling of authentication credentials.

Changes

• Implemented improved to_dict() and from_dict() methods in CollaborativeStormLMConfigs
• Added security measures to avoid serializing sensitive authentication data
• Improved CoStormRunner serialization to properly handle LM configurations
• Added support for persisting the report generated by knowledge base
• Ensured Azure authentication credentials are properly handled during deserialization

Benefits

• More reliable serialization/deserialization of session state
• Better security by not persisting sensitive authentication information
• Improved session restoration with proper LM configuration persistence
• Support for saving and loading completed reports

Testing

The changes have been tested by serializing and deserializing CoStormRunner instances with various configurations and verifying that the reconstructed instances maintain their functionality.

Fixes #328

[Yucheng-Jiang]

Thanks for contributing! We'll review the PR soon.