Rework "Hide online status" feature to cooperate with "Can Warn Staff" add-on (v2.0.8+ or later) to reduce number of queries required when viewing threads.
Now requires Can Warn Staff v2.0.8+ if installed.
Some pages may still have multiple queries per unique permission combination.
Add feature flag to disable the "[UserEss] Hide online status" permission, completely removing the need to query for other user's permissions.