Rebased PR of #810

[nmn]

What changed / motivation ?

#810 already exists but needs fixes and to be rebased. This is a PR to do that work so it can be merged.

Making a separate PR in case the original PR is updated in the meantime.

[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.9yrWDBCbVi /tmp/tmp.OUfMyqSNxc

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	567,110	567,110	1.00
· minified	10,232,512	10,232,512	1.00
rollup-example/.build/stylex.css
· compressed	100,626	100,626	1.00
· minified	757,176	757,176	1.00