Convert user profiles to Profile Panels

Summary:
Ref T10054. Primary goal is to be able to remove IconNav from the codebase.

I've made these non-editable so users can't customize them yet. We might want administrators to customize these globally instead? In any case, we avoid a bunch of product questions by just locking these down for now.

Test Plan:

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T10054

Differential Revision: https://secure.phabricator.com/D15020