Performance test set up

[jedmccaleb]

We would like to have a nightly, automatic performance test that runs in our staging network and replays history from genesis to present (and several other scenarios), comparing against benchmark values, in order to prevent performance regressions from entering production. When performance improves, benchmark values should be updated automatically, so that improvements are made permanent.

Ideally a subset of this test that can run in seconds-to-minutes should exist in workspace and per-commit integration-testing levels as well, so that simple / trivial performance regressions can be caught earlier still.