[Redesign] Sidenav, Crumbs, AppsNav

Summary:
First diff in the redesign branch, quick summary:

• Use full tiles on apps
• Shorten apps nav to standard sidebar width
• Shorten Conpherence nav
• Clean up styles around all navs
• Clean up styles around Crumbs

Test Plan: Viewed a number of pages on desktop, tablet and mobile. Will land in a redesign branch.

Reviewers: epriestley, btrahan

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9296