feat: migration to local NLP pipeline

[planshim]

This Pull Request is an effort to migrate away from Wit and roll out a more integrated and featureful NLP pipeline that would allow for higher control over its accuracy. Currently includes intent classification, answer validation, storing of documentation, retrieval of documentation from URLs, lookup of past questions and optional LLM integration.

Currently proposed as a draft with following things still in progress:

• Automated re-fetching of documentation added from URL
• Chunked documentation must belong to one document id
• Move away from vectra in favor of a different vector database
• All // TODO's from proposed implementation
• something else I didn't mention here?

This message is to be edited later with more details.

[PalmDevs]

also needs documentation for the new changes