Currently, whenever the page crashes, it emits an `'error'` event.
Error event is a special type of event in node.js; if unhandled,
it crashes the process.
Instead of emitting `'error'` event, this patch switches to emitting
`'crash'` event. Playwright users are free to handle the event
however they like, or just to ignore it.
Similarly to how we handle stdio, this captures all protocol messages and logs them when a test fails. Great for when debugging tests in parallel or for bot failures!
Currently I made `DEBUGP=true` turn this on locally, and turned it on always for the CI. Open to
suggestions for a better environment variable. I would turn it on by default always, like the stdio logging, but it adds an enormous amount of noise to our error messages.
