Improve width of apps launcher

Summary: Moves from 33% to 50% widths, allows more room for text on smaller screens. (Don't think this gets much use anyways). Fixes T6855

Test Plan: Reload page, shrink, still 50%

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T6855

Differential Revision: https://secure.phabricator.com/D11184