Stores the test/bench functions in rust op state during registration.
The functions are wrapped in JS first so that they return a directly
convertible `TestResult`/`BenchResult`. Test steps are still mostly
handled in JS since they are pretty much invoked by the user. Allows
removing a bunch of infrastructure for communicating between JS and
rust. Allows using rust utilities for things like shuffling tests
(`Vec::shuffle`). We can progressively move op and resource sanitization
to rust as well.
Fixes #17122.
Fixes #17312.