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 gpuweb/gpuweb#4809 has not landed yet.

Requirements for PR author:

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

Landed the spec; didn't make adapter and device use the same object, so we should test that adapter.info !== device.adapterInfo.

[beaufortfrancois]

The spec doesn't say they have to be different object, so I wouldn't test that adapter.info !== device.adapterInfo. Note that Chromium experimental implementation actually returns the same object: https://chromium-review.googlesource.com/c/chromium/src/+/5980752/3/third_party/blink/renderer/modules/webgpu/gpu_device.cc

[kainino0x]

It does implicitly require them to be different objects, because a new one is created the first time each of them is accessed, there's no opportunity to return the same one.

[beaufortfrancois]

I've updated this PR.
Do you know by any chance how to return a copy of adapter_->info() in Chromium?

[kainino0x]

We should construct the adapterInfo when we construct GPUDevice and store it in a field of GPUDevice, the same way we do for info when we construct GPUAdapter. The initialization will be the same so we should take this code, move it into a GPUAdapter method called something like CreateAdapterInfoForAdapter(), have it return the GPUAdapterInfo object, and then call it from both GPUAdapter::GPUAdapter and GPUDevice::GPUDevice.
https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/modules/webgpu/gpu_adapter.cc;l=198-210;drc=0afc9ac9afcaab79fc54299039f4d27abf3a086d

[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!