Remove collapsable option from ProfileMenu

Summary: Never really used this to full potential and takes up a lot of code and space. Remove option for now and make all profile nav menus small by default.

Test Plan: Review user, project, workboard. Set new menus.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Maniphest Tasks: T5867

Differential Revision: https://secure.phabricator.com/D17206