Description

This PR aims to offer a monitoring tool similar to the one available in Codalab. The following features have been developed:

The monitoring tool is only accessible by admins
It is accessible under the user menu -> analytics -> storage tab
3 metrics are available
- Usage history
- Competitions usage history and details
- Users usage history and details
Metrics can be download using the download buttons
The metrics only displays what has been computed by the server beforehand
2 background tasks has been coded:
- a reset task that get executed every 3 month (based on the value that is set in the settings/base.py). It reset the value of all computed file sizes so they will be re-computed again without any shifting on the next run of the storage analytics task
- a storage analytic snapshot task that get executed every week (based on the value that is set in the settings/base.py). It measures all files with unset size. Then it measures the storage usage per category (competition, user or admin) and per day. It then check for database <-> storage inconsistency (and created a log file in the logs/ folder). And save everything into the database so it becomes query-able by the front-end.

Issues this PR resolves