Simplify and document usage of a wasm-bindgen WebAssembly module in a Next.js app

[gthb]

Describe the feature you'd like to request

I want it to be fairly straightforward to use a Rust WebAssembly module created by wasm-bindgen in a Next.js project

Describe the solution you'd like

With reference to https://github.com/gthb/try-to-use-wasm-in-next.js/blob/main/README.md I would like:

1. the two apparent Next.js caching bugs to be fixed (if I'm right that they are Next.js caching bugs)
2. the Next.js documentation to contain a guide leading people through the apparent necessary steps, including guidance on what to do about SSR (making Node support WebAssembly there, or maybe avoid running WebAssembly on the server side if it's not absolutely necessary)
3. maybe some of those things working out of the box rather than requiring several scattered bits of obscure configuration (but yeah, I get that this is still a gradually maturing area...)

Describe alternatives you've considered

Building the Rust WebAssembly module differently or Babel-compiling it, so that it doesn't have import statements, so it doesn't need to be ESM. I did not quickly find success that way.

[gthb]

Note: I've realized that the wasm-pack output example I used in that writeup is old and doesn't reflect current wasm-pack output.

I have not yet succeeded in getting a simple ES module built by current wasm-pack to work under Next.js. I have just contributed an example to webpack demonstrating simple usage of such a module: webpack/webpack#14313 but trying to integrate that same module in Next.js I hit several roadblocks, which I am in the process of writing up in a concise way.

[gthb]

I hit several roadblocks, which I am in the process of writing up in a concise way.

See writeup and reproduction steps at #29362