chore(bidi): retrieve default context id from the browser

[yury-s]

Currently default user context id is always 'default', but the spec doesn't mention that, so we consider first available user context id as default.

This PR fixes some tests in defaultbrowsercontext-1.spec.ts for Firefox, e.g. 'should support viewport option'.

[github-actions]

Test results for "tests 1"

2 failed
❌ [webkit-library] › tests/library/video.spec.ts:441:5 › screencast › should work for popups @webkit-ubuntu-22.04-node18
❌ [webkit-library] › tests/library/video.spec.ts:475:5 › screencast › should scale frames down to the requested size @webkit-ubuntu-22.04-node18

4 flaky

⚠️ [firefox-library] › tests/library/inspector/cli-codegen-aria.spec.ts:76:7 › should update aria snapshot highlight @firefox-ubuntu-22.04-node18
⚠️ [firefox-page] › tests/page/page-evaluate.spec.ts:403:3 › should throw for too deep reference chain @firefox-ubuntu-22.04-node18
⚠️ [webkit-library] › tests/library/browsercontext-viewport-mobile.spec.ts:97:5 › mobile viewport › should fire orientationchange event @webkit-ubuntu-22.04-node18
⚠️ [webkit-page] › tests/page/page-screenshot.spec.ts:345:5 › page screenshot › should work while navigating @webkit-ubuntu-22.04-node18

38782 passed, 808 skipped
✔️✔️✔️

Merge workflow run.

[whimboo]

Currently default user context id is always 'default', but the spec doesn't mention that, so we consider first available user context id as default.

The WebDriver BiDi specification explicitly states that the default context has the id default:
https://w3c.github.io/webdriver-bidi/#default-user-context

@yury-s so it would be good to update the code to not just use the first returned context but the one with the id default.

[yury-s]

Currently default user context id is always 'default', but the spec doesn't mention that, so we consider first available user context id as default.

The WebDriver BiDi specification explicitly states that the default context has the id default: https://w3c.github.io/webdriver-bidi/#default-user-context

@yury-s so it would be good to update the code to not just use the first returned context but the one with the id default.

Thanks, updating in #35303