Fix show/hide applications on homepage

Summary:
Fixes T2482. After D4792, menus have more formal structure, but previously we were just shoving some <div> into the middle of the thing. This no longer works correctly, since we end up with <div class="nice-formal-div"><div></div>.

Just put IDs on all the items we're going to show/hide instead so we don't have to render any half-tags.

Test Plan: Home page show/hide works again.

Reviewers: btrahan, chad

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2482

Differential Revision: https://secure.phabricator.com/D4810