[Redesign] Normalize header policy and object tags

Summary: Ref T8099, This adds a consistent background color to object and policy tags, and highlights them when they deviate from the normal. Still likely worth revamping 'closed' and 'review' state colors.

Test Plan: Review lots of diffs and tasks.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T8099

Differential Revision: https://secure.phabricator.com/D13399