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.