LangChain LakeFSLoader: load document metadata tags

[Isan-Rivkin]

Problem

Currently our LakeFSLoader loads document without metadata object tags and only adds the logical path tag as source key to Document. We ignore any user set object metadata.

So What?

This means that the LakeFSLoader is not helpful the moment I need to use object metadata for embedding, retrieval etc.
For example, very common case in RAG of time weighted retriever.

To use the object tags I would have to implement custom logic for this listing all documents and getting the tags, bottom line it means I don't have a use in LakeFSLoader since I would have to load everything anyway myself.

Suggestion

When calling LakeFSLoader constructor in Langchain, add additional optional param to indicate id metadata tags should be added to the Document.

loader = LakeFSLoader(repo="...",ref="...",path="...", with_metadata=True)