When an install has spaces but a user has no access, roadblock them

Summary:
Ref T8449. If a user doesn't have access to any spaces, most applications just don't work, and they fail in confusing ways.

Just lock users out of everything explicitly up front with a clear message instead of letting them stumble into a big broken mess.

Test Plan: Locked a user out of all spaces, saw error to that effect.

Reviewers: btrahan, eadler

Reviewed By: eadler

Subscribers: eadler, epriestley

Maniphest Tasks: T8449

Differential Revision: https://secure.phabricator.com/D13545