Add "subgroup-size-control" feature

[Jiawei-Shao]

This patch adds the "subgroup-size-control" feature in gpuweb/gpuweb#5578.

[Jiawei-Shao]

@kainino0x @Kangz PTAL, thanks!

[Jiawei-Shao]

Hi @kainino0x and @Kangz ,

I cannot add subgroup-size-control because it hasn't been added to WebGPU SPEC and now CI requires the generated file must be up-to-date with gpuweb submodule.

[Kangz]

Let's not merge this before the feature is added to the spec, we can use Typescript casts to coerce the string into the enum type and temporarily bypass the typechecks when writing the CTS.