Add tests for GPUDevice.adapterInfo

[beaufortfrancois]

This PR adds simple tests for the adapterInfo GPUDevice member. It can be tested in a Chromium build patched with https://chromium-review.googlesource.com/c/chromium/src/+/5980752. It is available behind the "Unsafe WebGPU support" flag at chrome://flag#enable-unsafe-webgpu as the spec PR https://github.com/gpuweb/gpuweb/pull/4809 has not landed yet.

Requirements for PR author:

• [x] All missing test coverage is tracked with "TODO" or .unimplemented().
• [x] New helpers are /** documented */ and new helper files are found in helper_index.txt.
• [x] Test behaves as expected in a WebGPU implementation. (If not passing, explain above.)
• [x] Test have be tested with compatibility mode validation enabled and behave as expected. (If not passing, explain above.)

Requirements for reviewer sign-off:

• [ ] Tests are properly located in the test tree.
• [ ] Test descriptions allow a reader to "read only the test plans and evaluate coverage completeness", and accurately reflect the test code.
• [ ] Tests provide complete coverage (including validation control cases). Missing coverage MUST be covered by TODOs.
• [ ] Helpers and types promote readability and maintainability.

When landing this PR, be sure to make any necessary issue status updates.

[kainino0x]

Tested my changes in Canary with --enable-unsafe-webgpu, still works as expected.

[beaufortfrancois]

import { keysOf } from '../../../../common/util/data_tables.js'; is useful. Thanks for improving the PR!