R1:545dbabbcaa3

Improve application query UI/UX

Summary:
Ref T2625. @chad, you might have some feedback here. The behaviors this implements are:

- When the user selects "Advanced Search", we show the full search UI and no results (for performance and clarity).
- When the user submits a search which //is not// a named search, we show the full search UI and the "Save Custom Query..." button.
- When the user submits a search which //is// a named search, we show "Results for search X." with an "Edit Query..." button.