Description

This PR adds the storage quota per user feature.

It includes the following:

a new 'quota' field in the User model so each user has its own quota. It can, therefore, changed per a user basis
a global default quota variable defined in the settings of the app
the users' used space and quota is displayed on the resource page
checks has been added on every data upload (submissions, programs and bundles)
- the front send the the file size among other metadata to the back
- the back checks if it is ok to upload the file based on the remaining user quota
- if not ok an error is sent back to the frontend and is displayed to the user
using the django admin interface you can update the quota per user

Issues this PR resolves

Part of #713

To fake the size of a file you can overwrite the line 168 of the src/static/js/ours/client.js file