Make upload moves into a separate task

Have an independent task that performs the moving of the upload

Currently the moves are done while the user waits. This should be delegated to a separate task

Currently there are two options (not mutually exclusive):
- [ ] Have the code currently handling the upload start the new task for the upload
- [ ] Have a cron job to perform the upload

Other:
- Possibly, have a table in the database of upload move tasks that can be read by the cron job or the new task
- Drawbacks of starting new tasks, it makes it easy to flood the server with new tasks if many uploads need to be moved (does happen)
- A table would allow batching of upload moves
- Each move completion would have its own success/failure in-app message