Restrict error report download to files with errors

[elipe17]

Description:
It was recently pointed out that in the event a file is submitted and no errors are generated that the submitter can download an empty error report. This should be a little smarter. I.e. an error report should only be available to download if and only if the report has errors. The file attached below can be used as a test case for a file with no errors. When the file below is submitted the submitter is able to download an error report even though the file is Accepted and the error report has no errors.

MO_test_case_closed.txt

Acceptance Criteria:
Create a list of functional outcomes that must be achieved to complete this issue

• Error report can only be downloaded if it has data
• Error report link should or should not be available based on file status and error report content
• Testing Checklist has been run and all tests pass
• README is updated, if necessary

Tasks:
Create a list of granular, specific work items that must be completed to deliver the desired outcomes of this issue

• Update datafile serializer to return information about error report
• Update CaseAggregatesTable and TotalAggregatesTable to render a download link pending error report content
• Add frontend and backend tests
• Run Testing Checklist and confirm all tests pass