Add ability to upload data as file, including csv as binary

[SamGRosen]

A major motivation of the project was to allow researchers to avoid uploading potentially sensitive data to a remote server. We need to support the ability to upload data using the file input type. In addition, when uploading CSVs, it can be very wasteful to upload them as standard ascii files, i.e. a float with 7 decimal places will be represented by 9 or more bytes instead of 1. We need to consider a util for building csvs as binary files (such as in python, and then reading them in properly in javascript, potentially using FileReader.

Some libraries that may help could be Apache Arrow or flatbuffer.