Add ability to override __vitePreload chunk naming politics for SSR

[the-illarionov]

Clear and concise description of the problem

I've made lean versions of my chunks, without static VNodes (MyModule.js -> MyModule.lean.js), exactly like you did in VitePress.
But i can't override vite's logic of naming chunks.

Right now i've figured out hacky solution using nginx:

location ~ (^(?!.*(lean|index)).*)\.js$ {
  if ($cookie_page_mode = "") {
	  return 302 https://localhost$1.lean.js;
  }
}

And on client:

window.addEventListener("beforeunload", () => {
	document.cookie = "page_mode=spa;max-age=-1"
})

router.beforeEach(() => {
	document.cookie = "page_mode=spa"
})

But it feels soooooo dirty.

Suggested solution

It would be great if i could write something like that in vite.config.js:

preloadPolitics: {
    javascript: chunkPath => {
         return initialVisit ? chunkPath.replace(".js",".lean.js") : chunkPath
    }
}

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[sapphi-red]

I think this can be now archived by #9938.