[Redesign] Clean up spacing on Conpherence Menu

Summary: Ref T8099. This is a little more resilient to font size changes in the main UI.

Test Plan: Change font size in settings, items grow and align correctly.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T8099

Differential Revision: https://secure.phabricator.com/D13492