When running without tty, line reporter outputs a line for each
percent of the tests, thus limiting the output to ~100 lines.
In addition, reporters now support PLAYWRIGHT_LIVE_TERMINAL
env variable to force tty mode.
- Line reporter now shows stats in addition to the test name:
```log
[chromium] › page/page-click-react.spec.ts:108:1 › should not retarget when element changes on hover
23% [21/93] Passed: 17 Flaky: 0 Failed: 0 Skipped: 4 (7s)
```
- When connected to a TTY or with `env.PLAYWRIGHT_LIVE_TERMINAL`
set to anything but `'0'` or `'false'`, line reporter updates in place.
- When not connected to a TTY, line reporter prints an update
after each ~1% of tests done, so it never prints more than 100 lines.
- Updated tests to the golden style.
- `stdout.isTTY` controls whether list reporter updates lines or just adds them;
- `env.CI` is used in a few places to affect the defaults:
- whether to open interactive html;
- default reporter dot/line;
- default terminal reporter added to non-terminal reporters;
- `env.PWTEST_SKIP_TEST_OUTPUT` is removed;
- `env.PW_TEST_DEBUG_REPORTERS` is introduced specifically for tests.
