[Redesgin] Misc Inline Comment tweaks

Summary: Ref T8099. Better alignment with TODO and Ghost Icons.

Test Plan: Test more states of inline comments, ghosts, todos, unsubmitted, etc.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T8099

Differential Revision: https://secure.phabricator.com/D13515