Web UI for downloading template with data.

- Do not return 404 for uploads, return empty list instead.
- Make download with data a button.
- Return edn when queued download. Add alerts.
- Add downloads ns and add new routes for downloading files and statuses.
- Add subdirectories for storign files in s3
Fix file leakage and tidy up.
Fix typos.
Merge pull request #112 from MastodonC/feature/template-with-data-ui

Feature/template with data ui