feat: add cookies.setFromString to create a cookie from a string

[while1618]

here is the issue for this PR: #13680

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[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-kit-13681-svelte.vercel.app/

[github-actions]

pnpm add https://pkg.pr.new/@sveltejs/adapter-auto@13681
pnpm add https://pkg.pr.new/@sveltejs/adapter-cloudflare@13681
pnpm add https://pkg.pr.new/@sveltejs/adapter-netlify@13681
pnpm add https://pkg.pr.new/@sveltejs/adapter-static@13681
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pnpm add https://pkg.pr.new/create-svelte@13681
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pnpm add https://pkg.pr.new/@sveltejs/kit@13681
pnpm add https://pkg.pr.new/@sveltejs/package@13681

[changeset-bot]

🦋 Changeset detected

Latest commit: 0d3f8fd

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@sveltejs/kit	Minor

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