chore: Next.js + CLI example

[nmn]

Added a Next.js example that uses the CLI for compilation.

NOTE: Because of some strange NPM issues, the Next build fails with some strange errors. The CLI is not the root cause and the previous Next example has fallen into this before.

So, for now, this PR is not intended to be merged. It's primarily a test to ensure that the CLI does work for a Next.js app.

[github-actions]

compressed-size: runtime library

Size change: 0.00 kB
Total size: 2.52 kB

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Filename: gzip (minify)	kB size	kB change	% change
./packages/stylex/lib/stylex.js	1.04 (3.22)	0.00 (0.00)	0.0% (0.0%)
./packages/stylex/lib/StyleXSheet.js	1.48 (3.75)	0.00 (0.00)	0.0% (0.0%)

[github-actions]

compressed-size: e2e bundles

Size change: 0.00 kB
Total size: 1128.74 kB

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Filename: gzip (minify)	kB size	kB change	% change
./apps/rollup-example/.build/bundle.js	1005.32 (10185.35)	0.00 (0.00)	0.0% (0.0%)
./apps/rollup-example/.build/stylex.css	123.42 (774.34)	0.00 (0.00)	0.0% (0.0%)