This changes the root object from RemoteBrowser to Playwright,
similar to local driver connection. This way, any remote connection
gets a Playwright object.
This also starts reusing PlaywrightServer class, and introduces
`cli run-server` hidden command that runs ws server on the
specified port.
Previous structure:
```
RemoteBrowser
- browser (using ConnectedBrowser for remote-specific behavior)
- selectors (special instance for this remote connection)
```
New structure:
```
Playwright
- ...
- selectors (special instance for this remote connection)
- preLaunchedBrowser (using ConnectedBrowser for remote-specific behavior)
```
api(trace): introduce artifacts options
This introduces launch({ artifactsPath }) and newContext({ relativeArtifactsPath, recordTrace }) options.
- artifactsPath option controls the directory where all artifacts go. If not passed, artifacts are not collected.
- relativeArtifactsPath can be used to put context-specific artifacts into a subfolder. If not passed, shared artifactsPath is used.
- recordTrace controls trace recording.
We also expose trace types under playwright/types/trace.d.ts.
In the follow up:
- videos will be put into artifactsPath;
- downloads will be put into artifactsPath, or keep using existing downloadsPath when artifactsPath is not specified.
Root index.js is only used for local development, so
assuming dev mode there is fine. This way we do not have
to worry about calling setUnderTest early enough.
