Add support for "tools" (function calling)

[samkeen]

For the LLMs which support function calling

https://docs.anthropic.com/en/docs/build-with-claude/tool-use https://platform.openai.com/docs/guides/function-calling

• Add the ability to add tool arguments in the request builder
• enable access to the tool args in the result

[samkeen]

added a Tool builder

next enable access to tool request results.