adding youtube tool

[leondape]

Summary

A Youtube Tool for Agents to use.
It uses youtube API and a transcription NPM package.
Usage is quite simple for 4 methods

• getting youtube info
• searching for videos
• getting transcripts (very useful for video summary)
• get comments

I am not too familiar with what tools/util/handleTools.js does. I figured it was required to "ask for" user provided API keys if they are not provided by env variable. But probably I overconfigured it.
Please give feedback on what is actually required there or simply remove useless parts.

Change Type

• New feature (non-breaking change which adds functionality)

Testing

I figured that unit tests for tools are not really possible, there are no other tests for tools yet?

Checklist

Please delete any irrelevant options.

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• I have commented in any complex areas of my code
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective or that my feature works
• Any changes dependent on mine have been merged and published in downstream modules.
• A pull request for updating the documentation has been submitted.

[danny-avila]

looks good! hope to try it soon

[leondape]

Cool!
Please take extra care in handleTools.js as I did not totally understand what I did there.
Like what is really required and what not.