Integrate user repository with admin api

Rather than retrieving user permissions from the config file get them
from the UserRepository.
Fix EVL feature tests

Add steps to configure upload filters and allow access to the buckets.
These tests could not work before but it wasn't noticed because the
upload features have been disabled due to the fact we can't set the
content type on uploads. This was tested by allowing octet-stream.
Update seed tool to generate user seed
Update seed loading task and add user task

- Update the `load_seed` task to also load the user seed file
- Add a new task to add user permissions