As a User, I can add PDF files to the vector database

[NotNeelPatel]

Description
Add PDF upload support to CityAgent

Acceptance Criteria
Users can upload PDFs to the vector database, chunked appropriately (e.g. by paragraph or section).

CRUCIAL: Metadata contains the date that it was last updated (ie, when it was uploaded)

Test Thoughts

• Attempt to add PDF files
• Ask the agent about the PDF file

Developer Thoughts
Check out unstructured
You're going to have to play around with chunking