R1:1a001ca03379

Render ApplicationSearch errors correctly

Summary:
Fixes T8774. When an ApplicationSearch page returned an error (e.g., using a "viewer()" query while logged out), we would try to add action links to a box without a header. Instead:

- If a box has no header, but has show/hide actions, just create an empty header so the view renders. This is a little silly looking but does what the caller asks.
- Always set the title on the result box, so we get a header.

Test Plan: Did an invalid (logged out, with…