R1:3c19004f9f41

Fix blur and sort behavior for autocomplete

Summary:
Ref T10163.

- If you click a result, we get a blur before your click hits, and deactivate before the click can work. Instead, wait before responding to blur.
- Use the standard sort handler which puts unixnames over human names. Also use the standard filter which deals with disabled users not matching unless they're the only match.

Test Plan:
- Clicked a result, got a replacement.
- Named myself "dog dog", typed "@dog", user "@dog" was now…