File upload refactor

Forked from #2 (closed)

  • Create cancel button, which calls DELETE request for aborting file upload
  • Prevent user to leave the page while upload, call DELETE if user leaves anyway
  • Progress bar for uploading (per file)
  • Resume upload from where it stopped if failed (per file)
  • provide etag per chunk and per file
  • create new submission statuses (see below)
Edited by Kamile Liucija Vainiute