[simple] add duckduckgo to load_tools.py

[skcoirz]

• duckduckgo was introduced in Harrison/ddg #3206, but it’s not enabled in load_tools.py yet.
• this PR simply enables it in load_tools.py with a straightforward agent call (as described in get_started doc) to verify the functionality.
• duckduckgo integration test passed.

TODO:

• not seeing an agent specific integration. Since I’m still ramping up here, will add it in a following PR.
• it looks like DuckDuckGo is using a different naming convention with postfix “-Tool” vs “-Run” comparing with others. The work is straightforward and it is a great way to explore the codebase, so I decided to take the chance to deeply read the codebase and then make the straightforward change in the next PR. :)

This is my first PR. Please let me know if there is anything I can improve. Thank you so much!

Agent Call with DuckDuckGo instead.

[skcoirz]

trunk has a lint error. fixed it in the latest commit.

TODO: will add missing annotation to the rest variables. It will touch a lot of them. So to keep the commit focus and clear, I’ll do them in another PR.

[skcoirz]

thank you for accepting my PR, @vowelparrot ! I found there is a lint error in the latest trunk. Just fixed it in one of the commit here. Please take a look when you have time. As commented above, I’ll add annotation to the rest variables in the file to keep them consistent. Thanks!