Added DuckDuckGo Search Tool and Agent in AutoGen Extensions

[varadsrivastava]

Why are these changes needed?

Adds a specialized AutoGen agent that uses DuckDuckGo for web searches, providing privacy-focused search capabilities without requiring API keys.

Related issue number

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://github.com/microsoft/autogen/blob/main/CONTRIBUTING.md to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

[varadsrivastava]

@microsoft-github-policy-service agree

[varadsrivastava]

Hi Eric (@ekzhu), really appreciate your help and review on this one! :) Could you please let me know if there's anything else needed before we could merge this?

[ekzhu]

@varadsrivastava there are still many issues with the PR. If you are using code generation tool I recommend adding existing unit tests as part of the context to properly generate unit tests. Also, make sure to run type checks and unit tests locally before requesting for review.

I am fixing this for you this time. In the future please follow the developer guide.

[codecov]

Codecov Report

Attention: Patch coverage is 89.89362% with 19 lines in your changes missing coverage. Please review.

Project coverage is 80.42%. Comparing base (0bd99ee) to head (07a3eac).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
.../tools/web_search/duckduckgo/_duckduckgo_search.py	88.19%	19 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6682      +/-   ##
==========================================
+ Coverage   80.33%   80.42%   +0.09%     
==========================================
  Files         232      234       +2     
  Lines       17688    17863     +175     
==========================================
+ Hits        14209    14367     +158     
- Misses       3479     3496      +17     

Flag	Coverage Δ
unittests	80.42% <89.89%> (+0.09%)	⬆️

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[ekzhu]

Dear @varadsrivastava, unfortunately we had to remove these changes from our code base because of potential DMCA violation. You are welcome to contribute it as an independent package autogen-ext-duckduckgo-search and publish the source code to GitHub with tag autogen for discovery.