Add support for HuggingFace embeddings (i.e. HuggingFaceEmbedder)

[brenkao]

Is your feature request related to a problem? Please describe.
Similar to HuggingFaceCall, you can already extend OpenAIEmbedder to use huggingface models.

class HuggingFaceEmbedder(OpenAIEmbedder):
    embedding_params = OpenAIEmbeddingParams(model="nomic-ai/nomic-embed-text-v1.5")
    api_key = "-"
    base_url = "http://localhost:8080"

but would be nice to have direct integration.

Describe the solution you'd like
An embedding interface similar to OpenAIEmbedder that extends BaseEmbedder, but with more direct integration with huggingface text-embeddings-inference.

Additional context
Here is the API reference.
https://huggingface.github.io/text-embeddings-inference/#/

[willbakst]

Similarly closing this issue as we have no current plans to take RAG out of beta (other than potentially something with Postgres, but uncertain).

If there's enough reason to build this, we can reopen the issue.