wasm-bindgen-test-runner: redirect worker console

[drewcrawford]

wasm-bindgen-test-runner redirects the console for the test thread onto native CLI. However in my testing, further workers (such as spawned via wasm_thread) are not redirected, causing all other logs to be dropped in native CLI which is highly misleading for a CLI-based workflow.

proposed solution

• Some API like `wasm_bindgen_test_runner::hook_console() that hooks the console on arbitrary threads if not already
• Could be implemented by wasm_thread or by users to unblock their debugging workflows

Intent to solve out of tree

This is the third issue I've filed in this project:

• Fix wasm-bindgen-test compatibility with doctests in Node.js #4535 is a PR which solves a bug
• wasm-bindgen-test: Support sharing WebAssembly modules and memory between workers #4534 needs design decisions from maintainers

This is my announcement that I will no longer be routinely filing bugs in this repository until and unless a material change in policy happens upstream. Interested parties can contact me separately for license-compliant out of tree unofficial patches on various topics.