Restrict aprhont-form-width to certain input types
Summary: Fixes T11491, I believe these are the only two that need to be specified.
Test Plan: Checked Create pages for diffs, tasks, projects, events, blogs, login, etc. Mobile/Desktop.
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: Korvin
Maniphest Tasks: T11491
Differential Revision: https://secure.phabricator.com/D16416