feat: add support for ECMAScript modules in the JavaScript kit

[Angelmmiguel]

Thanks to the new Javy version, we can now eval JavaScript modules with the eval_module method. To use this new method, I had to update the javy version to 2.0.0. The upgrade caused some errors in the build process due to crate incompatible versions (wasmtime-wasi requires bytes = "^1.4" while javy requires bytes = "=1.1.0". Since I consider these two projects as separate entities, I just excluded it from the workspace.

Finally, I added a new js-modules example that showcases it.

It closes #149

[ereslibre]

LGTM as a first approach, I think we can improve later.

[ereslibre]

I guess this is fine for our purposes now, but this would identify a comment "// export default" as so, even if it wasn't really JS code.

[Angelmmiguel]

You are totally right. This is a limitation on the current implementation. For now, I believe it's fine as the biggest issue should be a failed response from wws. Detecting a comment would be more complex as you can write multi-line comments in JS with the /* ... */ syntax. We would need to detect the following code too:

/*
export default app;
*/

This is a task for a JS parser, but I would avoid adding this dependency unless is strictly necessary. The reason is that it adds complexity and affects the performance. If we find more edge cases that requires it, we may decide to add the parser like the Javy CLI tool.

[Angelmmiguel]

I also added a third regex to detect exported objects like:

export default {
  async fetch() {
    // ...
  }
}

[ereslibre]

LGTM modulo the windows CI