Update bearer tokens by type or group

Small class for mass updating data sets (so far by data group and type name but easy to extend)

- I don't like complex queries in models, I like query objects
- The class method name may be a bit long but I like being verbose if it's descriptive

Manage command with error handling and tests.

Go on, destroy something beautiful.

Run it:

`python manage.py set_token token --data-type-name=monitoring --data-group-name=abcd`