Rollup example styles using 'property-specificity' style resolution

[necolas]

What changed / motivation ?

Demonstrate impact on JS bundle size of styleResolution being 'property-specificity' rather than the default of 'application-order'.

Additional Context

'application-order' generates hundreds of null values in the compiled JS output.

'property-specificity' doesn't do this and lends itself to more compact CSS bundles too.

[github-actions]

workflow: benchmarks/size

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

@stylexjs/[email protected] size:compare
./size-compare.js /tmp/tmp.qyYyphKelX /tmp/tmp.yC4ezMpNAX

Results	Base	Patch	Ratio
stylex/lib/stylex.js
· compressed	899	899	1.00
· minified	3,223	3,223	1.00
stylex/lib/StyleXSheet.js
· compressed	1,258	1,258	1.00
· minified	3,748	3,748	1.00
rollup-example/.build/bundle.js
· compressed	563,563	504,676	0.90	!!
· minified	10,185,348	5,725,352	0.56	!!
rollup-example/.build/stylex.css
· compressed	100,211	100,185	1.00	-
· minified	759,868	760,063	1.00	+

[nmn]

compressed | 563,563 | 504,676 | 0.90

So it looks like it saves 10% of the JS bytes in this case, if I'm reading the table right?

Should we add a new example so we can maintain a comparison going forward? There are some further optimisations that can be made to the 'application-order' case as well.

[necolas]

I think we should be working to get rid of the options and standardize on property-specificity