tools,doc: add support for several flavors of JS code snippets

[aduh95]

Enable code example using both modern ESM syntax and legacy CJS syntax.
It adds a toggle on the web interface to let users switch from one JavaScript flavor to the other.

html.js detects code snippets with a meta attribute:

```mjs
export default {};
```
```cjs
'use strict';
module.exports = {};
```

And adds a <input type=checkbox> toggle:

With dark mode on

• ✅ Doesn't require JavaScript on the client.
• ✅ Doesn't break the accessibility of the docs.
• ✅ Doesn't break GitHub auto-highlighting (well it breaks in the code diff, but it renders OK in the markdown preview, see https://github.com/aduh95/node/blob/doc-multi-syntax-snippets/doc/api/wasi.md).
• ❓ Use non-free content (the toggle used in this PR is derived from https://fontawesome.com/icons/toggle-on?style=solid, which is under CC BY 4.0 License).

Originally suggested by @jasnell in #37077 (comment).

[aduh95]

@nodejs/documentation @nodejs/website wdyt?

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/36322/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/36324/

[aduh95]

Adding the blocked label, as this implementation is probably going to conflict with the next linter update. I'll update this once nodejs/remark-preset-lint-node#176 lands on nodejs/node master.

[aduh95]

433badd is part of #37604, this PR needs to wait for the other one to land first, other than that it should be ready.

//cc @nodejs/documentation

[jasnell]

#37604 has landed now :-)

[aduh95]

Landed in 2e1e74e