I've added support for `new URL(..., import.meta.url)` pattern accepted by many bundlers to wasm-bindgen and Emscripten, both for Wasm files as well as for side Workers autogenerated to support multithreading.
On the apps side like Squoosh this means we no longer have to manually specify URLs to be passed to wasm-bindgen or Emscripten init functions. In this PR I'm primarily doing just that - removing all the manual Wasm URL locators, as well as the associated logic.
One notable change on the build system side is that, in order for Wasm and multithreading-related Workers to be detected as dependencies, I'm now walking over `referencedFiles` in addition to `imports` when collecting list of dependencies in `getDependencies` function (client-bundle-plugin.js).
As a side effect, it also included other linked assets - images and CSS - which simplified quite a few caching lists in to-cache.ts as well. Instead of having to manually specify each asset that needs to be included, the logic is inverted and only few extra assets had to be excluded to keep the list of in items cached on the first load as low as it was before the change.
All in all, I think this simplification is worth it and even helped to accidentally uncover & fix one caching bug where WP2 regular JS was cached in addition to WP2 multithreaded JS simultaneously.
This is by no means a proper fix, but Chrome 91 (stable tomorrow) brings some breaking changes to SIMD, and I'd rather disable SIMD for now to avoid breaking Squoosh altogether once it hits stable, and work on a proper fix in a separate branch.
