Provide local Search API option

[miurla]

Feature Description

As an alternative to the Tavily search API, use SearcXNG to provide a local search API. Since SearcXNG returns meta-search results, make it usable from LLM by embedding.

Use Case

Use it as an option for the search API when launching locally. It has advantages in terms of cost and privacy.

Additional context

refs: #34 #175

[GobDevv]

https://github.com/Snazzah/duck-duck-scrape

Possibly DDG support?