feat: enable adding tools from huggingface (smolagents)

[jakelorocco]

Add a MelleaTool.from_hugging_face to add tools from huggingface/smolagents: https://huggingface.co/docs/smolagents/en/tutorials/tools.

I believe this should just be a wrapper around their load_tool and/or from_hub function; but a deeper investigate is necessary.

[ajbozarth]

I'll start looking into this