add CSV file upload

[lkeegan]

User needs to upload a csv file as well as a h5 file.

CSV file can/should be validated to include columns with names:

• barcode
• cdr3
• chain

[lkeegan]

Could potentially do this validation in javascript:

• https://developer.mozilla.org/en-US/docs/Web/API/FileReader
• https://stackoverflow.com/questions/19280901/javascript-upload-and-parse-file-on-fly