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

View unchanged

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

View unchanged

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%)

[github-actions]

workflow: benchmarks/size

Comparison of minified (terser) and compressed (brotli) size results, measured in bytes. Smaller is better.

@stylexjs/scripts@0.9.3 size:compare
./size-compare.js /tmp/tmp.Fky0mPnlBa /tmp/tmp.MYzGpQUK6I

Results	Base	Patch	Ratio
stylex/lib/stylex.js
· compressed	729	729	1.00
· minified	2,541	2,541	1.00
stylex/lib/StyleXSheet.js
· compressed	1,266	1,266	1.00
· minified	3,776	3,776	1.00
rollup-example/.build/bundle.js
· compressed	563,025	563,025	1.00
· minified	10,185,368	10,185,368	1.00
rollup-example/.build/stylex.css
· compressed	99,154	99,154	1.00
· minified	745,649	745,649	1.00