Add AllFeaturesMaxLimitsGPUTest

[greggman]

This is a test that requests all features and maximum limits. This should be the default test for the majority of tests, otherwise optional features will not be tested. The exceptions are only tests that explicitly test the absence of a feature or specific limits such as the tests under validation/capability_checks.

As a concrete example to demonstrate the issue, texture format rg11b10ufloat is optionally renderable and can optionally be used multisampled. Any test that tests texture formats should test this format, skipping only if the feature is missing. So, the default should be that the test tests kAllTextureFormats with the appropriate filters from format_info.ts or the various helpers. This way, rg11b10ufloat will included in the test and fail if not appropriately filtered. If instead you were to use GPUTest then rg11b10ufloat would just be skipped as its never enabled. You could enable it manually but that spreads enabling to every test instead of being centralized in one place, here.

Honestly, I'd prefer to rename GPUTest to SpecialGPUTest or possibly even DeprecatedGPUTest it clear not to use it and where it needs to be fixed and then name this GPUTest. But, we can do that later. For now, I just effectively replaced MaxLimitsTestMixin with AllFeaturesMaxLimitsGPUTest in the places where it could easily be replaced.

The remaining places bring up an issue. All of them are based on ValidationTest. I think the same rules apply. For example, if we're validating that textures fail validation for certain reasons we should be checking formats that are optional also pass the same validation rules. The simplest way to do that would be to make ValidationTest inherit from AllFeaturesMaxLimitsGPUTest.

Unfortunately, the capability_checks/* are all based off ValidationTest so they need to be moved to something else before we can make that change.

Issue: #4178

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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.

[shrekshao]

Honestly, I'd prefer to rename GPUTest to SpecialGPUTest or possibly even DeprecatedGPUTest it clear not to use it and where it needs to be fixed and then name this GPUTest. But, we can do that later. For now, I just effectively replaced MaxLimitsTestMixin with AllFeaturesMaxLimitsGPUTest in the places where it could easily be replaced.

Sounds good

[shrekshao]

LGTM