feat(rosetta): Rosetta manages dependencies automatically

[rix0rrr]

It's quite an annoying bother and pretty brittle to have to set up a full dependency directory to compile examples in.

In CDK, we use the directory of the decdk package to do this, because we have external knowledge that all packages
will be symlinked into this directory.

That mechanism is brittle and revolves around having outside knowledge. Instead, make Rosetta manage the dependency closure itself, when user declare exampleDependencies in package.json:

{
  "jsiiRosetta": {
    "exampleDependencies": {
      "@some-other/package": "^1.2.3",
      "@yet-another/package": "*",
    }
  }
}

It is not necessary to redeclare any of the dependencies and peerDependencies already in package.json: those are automatically included.

---

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[mergify]

The title of this Pull Request does not conform with [Conventional Commits] guidelines. It will need to be adjusted before the PR can be merged.
[Conventional Commits]: https://www.conventionalcommits.org

[mergify]

The title of this Pull Request does not conform with [Conventional Commits] guidelines. It will need to be adjusted before the PR can be merged.
[Conventional Commits]: https://www.conventionalcommits.org

[RomainMuller]

allTypeScriptSnippets returns a promise to an array already...

Suggested change

	const snippets = Array.from(await allTypeScriptSnippets(assemblies, true));
	const snippets = await allTypeScriptSnippets(assemblies, true);

[mergify]

Thank you for contributing! ❤️ I will now look into making sure the PR is up-to-date, then proceed to try and merge it!

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Merging (with squash)...

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Merging (with squash)...