feat: add Faiss as VectorStore provider

[ewfian]

Add support for Faiss and also implemented a loadFromPython method, which can read VectorStore saved from Python's implementation.

TODO:

• [X] Improve the pickle parser and fully implement Pickle protocol version 4. Extract pickle.js as an NPM package and then import it. The package will be here pickleparser.
• [x] Port id to uuid mapping from Python implementation.
• [x] Save mapping into JSON file.
• [x] Add examples.
  • [x] Create a new index from texts.
  • [x] Create a new index from a loader.
  • [x] Save an index to file and load it again.
  • [x] Load the saved file from Python.
• [x] Add test cases.
  • [x] Unit Test: fromTexts + addVectors.
  • [x] Unit Test: fromDocuments + addVectors.
  • [x] Unit Test: exceptions.
  • [x] Integration Test: save and load.
  • [x] Integration Test: Load from Python.
  • [x] Integration Test: Add documents after loaded from Python.
  • [x] Integration Test: Save and re-load after loaded from Python.
• [x] Add documentation.
  • [x] Create pages.
  • [x] Add basic information.
  • [x] Add example for how to read from Python.

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Name	Status	Preview	Updated (UTC)
langchainjs-docs	✅ Ready (Inspect)	Visit Preview	May 18, 2023 4:53pm

[nfcampos]

Thanks a lot for this @ewfian this is a great PR, sorry for the delay in getting this in