Remove sessions of demoted or deleted users

[Tbaile]

When deleting or demoting a user, clean up the directory with the tokens of said user.

[Tbaile]

QA: create an admin user other than root, then open a incognito window to log in the account of the created user

Proceed by checking that everything works fine, then disable the user from the root account: assert that the user blocked is locked out of the administration page.

Run the same check twice, by re-enabling the user, checking that auth works and it's possible to access the UI. From the root account now, delete the user and check that it's being locked out.

[m-dilorenzi]

1. user created

2. log in with the new user

3. after removing the administration option from the test_admin user

4. log out and log back in with the user as a non-admin user → login is no longer possible

5. set the test_admin user as admin again
6. log back in to the firewall correctly with the test_admin user again

Verified