Support for HF models

[iterix]

Currently auditor supports LLM providers via Langchain. However, we need to support HuggingFace models as well so that users can audit open-source or fine-tuned models as well

[crodriguez1a]

FYI, Lanchain supports custom LLMs which may be a workaround. https://python.langchain.com/docs/modules/model_io/models/llms/how_to/custom_llm