Add csv file type for document upload

[elaineg]

What feature(s) would you like to see?

Current behaviour: The default file upload tool added to the toolkit only parses PDFs.

Expected behaviour:

1. Add a tool that can parse csv files into string and send to model into available default tools
2. When a csv is uploaded, automatically select the csv file tool to be used with it (similar to PDF)

We would love to see even more file types supported but I will close this when csv is supported.

Additional information

No response