Integrates Bing as a new search engine option alongside existing engines like DDG, Exa, and Tavily. This provides users with more choice and improves the robustness of the web search tool.
- Adds `BingSearch` class and its integration into the `WebSurfingTool`.
- Implements the `_search_bing` async method to handle search queries via the Bing scraper.
- Updates the search strategy logic to include "bing" as an option.
- Modifies the tool cache key generation to use the file path for better uniqueness.
- Updates the configuration template to list "bing" as an available search engine.