Add functionality to upload pdf files to web server

[aaroosh-07]

Description

To perform question answering task on pdf file, we need to upload the file to web server. After this web server can prompt LLM model to using pdf file as context.

Discussion needed

• Will we store uploaded file locally on the web server or store it in a cloud application such as AWS S3.
• Do we need to cache the chunks created using the content of uploaded files

Acceptance Criteria

• User is able to upload pdf file to server and server breaks the content into chunks which can be passed to LLM for inference
• User is able to perform question answering task on uploaded file.