FEAT: add tavily tool for searching... A search engine for LLM

[Yash-1511]

Description

Add a Tavily Search Tool. Tavily API is a search engine built specifically for AI agents (LLMs), delivering real-time, accurate, and factual results at speed.

Fixes # (issue)

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update, included: Dify Document

How Has This Been Tested?

I have done manual testing. Like providing some recent news queries and giving task to summarize this new article.

• TODO

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods
• optional I have made corresponding changes to the documentation
• optional I have added tests that prove my fix is effective or that my feature works
• optional New and existing unit tests pass locally with my changes

[crazywoola]

Hello there is a lint error in this pr.

[Yash-1511]

Hello there is a lint error in this pr.

Done! Fixed it