We used to not report fatal error and hang forever because worker
did not run any tests but also did not report any errors.
Also properly show stack-less errors.
Each hook gets its own test scope. This is not too useful for
object fixtures like `page` (although one can use a page in
`beforeAll` to save storage state), but much more useful for option
fixtures like `viewport`.
We now have Suites and Tests. When running multiple projects the whole
suite is cloned for each project. Same happens for repeatEach.
This simplifies the reporters API, but there is still room for improvement.
JSON reporter continues to produce old json output.
- Source now lives at `src/test`.
- Former folio tests live at `tests/playwright-test`.
- We use `src/test/internal.ts` that exposes base test without
Playwright fixtures for most tests (to avoid modifications for now).
- Test types live in `types/testFoo.d.ts`.
- Stable test runner is installed to `tests/config/test-runner` during `npm install`.
- All deps including test-only are now listed in `package.json`.
Non-test deps must also be listed in `build_package.js` to get included.
