Keyboard-tab out of search box should minimize search box (& tab into should maximize it)

[kellyi]

Overview

The search box should expand or minimize appropriately as the keyboard tabs through it:

• when I press tab to enter the search box, it should maximize
• when I press tab to exit the search box, it should minimize

Expected Behavior

• when I press tab to enter the search box, it should maximize
• when I press tab to exit the search box, it should minimize

This is the current behavior when using the mouse, which the keyboard should replicate.

Actual Behavior

When I tab through the search box its state remains the same: it's maximized in all cases until I use the mouse to focus elsewhere.

[kellyi]

Discussed this with Scott and it contravenes the desired behavior cataloged in #6. Rather than spending more time trying to tweak this, going to mark it as blocked for now and then we can revisit later when we get some feedback on how they work in PV & SI from PWD.