feat: Add progress reporting for long-running operations

[gns-x]

Add a progress reporting system to provide visibility into long-running operations like topic identification and statement categorization. This improves the user experience by adding a ProgressReport interface, implementing progress callbacks, and including comprehensive tests and documentation.

[gns-x]

I've signed the CLA and would like to contribute this progress reporting feature to improve the user experience of the library.

This PR adds a progress reporting system that helps users monitor long-running operations like topic identification and statement categorization. The implementation includes:

1. A new ProgressReport interface for structured progress updates
2. Progress callbacks in the Sensemaker class
3. Progress reporting for both topic identification and statement categorization
4. Comprehensive test coverage
5. Updated documentation with usage examples

The feature is particularly useful for:

• Monitoring progress of large-scale analysis tasks
• Providing better visibility into long-running operations
• Making the library more suitable for production use

I'm happy to make any adjustments or improvements based on feedback. Thank you for reviewing this PR!