Allow all uploaded documents (student and employer) and completed forms to be exported for an experience

Some schools are currently creating a final "packet" for each student that includes this information. Instead, we could either combine all PDF files into one "packet" and/or allow all files to be exported to a ZIP file.

In some instances, this is needed for state reporting/auditing purposes and if it were possible to do for multiple experiences simultaneously, that would be an added benefit.