Enhance researcher agent with dual-mode query construction and deep dive action handling

- Added support for dual-mode query construction based on search mode (funded_projects or ghgi_data).
- Incorporated deep dive actions for scraping and crawling directly from the state metadata.
- Improved logging for query construction and deep dive actions.
- Updated the collect_search_results function to handle new parameters and state for better search mode detection.
- Enhanced error handling and logging throughout the scraping process.
- Refactored code for clarity and maintainability, including import organization and function documentation.

Author: piotrnowakowski