fix(open in codesandbox button): optimize for long sandoxes

[danilowoz]

This introduces a breaking change due to useCodeSandboxLink is no longer used to generate the URL. From now on, the UnstyledOpenInCodeSandboxButton is responsible for managing the URL or the form that will create a new sandbox in the CodeSandbox.

In the previous approach, all the parameters to create a sandbox in the CodeSandbox were attached directly in the URL, making it easily reach the request too long (401). That's why we deprecated the hook in favor of using a whole new component, which is responsible for either using an anchor (for short sandboxes) or a form-POST (for long sandboxes).

The UnstyledOpenInCodeSandboxButton is a basic component that doesn't carry any style, so if you want a ready-to-use component, use the OpenInCodeSandboxButton instead, which contains the CodeSandbox logo and the same functionality.

---

Migration guide:

import {
--  useCodeSandboxLink,
++  UnstyledOpenInCodeSandboxButton
}
const CustomOpenInCSB = () => {
--  const url = useCodeSandboxLink();
--  return <a href={url}Open in CodeSandbox</a>
++  return <UnstyledOpenInCodeSandboxButton>pen in CodeSandbox</UnstyledOpenInCodeSandboxButton>
   );
};

CSB-519

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[alexnm]

Left a few comments, but nothing to block the PR if you have other priorities right now

[daryl-cecile]

It seems the export for useCodeSandboxLink in 'sandpack-react/src/hooks/index.ts' needs to be removed

[andreifloricel]

Hi @danilowoz, I just stumbled on this limitation (401 on long requests) and wanted to open an issue but then noticed this PR :)
Is this fix planned for a coming release?

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[sannek]

Some small docs suggestion ❤️ Looks great tho!