User RESTRICTED status
Summary:
Restricted flag for new users
Fix the user:resync test that was removing existing users
Display Restricted badge on user page for admins
Update Dusk, fix flaky test
Test Plan: ./phpunit
Reviewers: #hkccp_developers, mollekopf
Reviewed By: #hkccp_developers, mollekopf
Subscribers: mollekopf, #hkccp_developers
Differential Revision: https://git.kolab.org/D4057