R1:6aac9f99d7fe

Quicksand - get the dark console working properly with quicksand

Summary:
Fixes T7700.

This ends up being kind of tricky because

- the key for a given request is only correct at the time the dark console is rendered
- the dark console itself should contain every request made, as opposed to being drawn from scratch
- in the case of a quicksand request, the behavior gets invoked first with the correctly rendered console as part of the `quicksand-redraw` event and then again shortly after as an ajax…