BeforeAll/AfterAll hooks

This should be doable with once-per-process semantics as we have in cucumber-js. So for `--test-isolation=none` it would be just once, and by default it would be once per process, meaning once per feature file since this is how Node.js does the split.

https://nodejs.org/api/test.html#global-setup-and-teardown is how we should be able to hook into the lifecycle.