[breadbox] Snowpack replacement

[ChristopherBiscardi]

Snowpack has deviated too far away from its original goals of being a third-party npm package esm bundler. It now handles everything from sass to css modules to hot module reloading and every framework under the sun. We only need the third-party esm bundling.

short-term: Continue to use breadbox
long-term: move to our own implementation
super-long-term: hopefully this code is no longer required in 3-5 years.

Long Term

SWC has spack, which might be good enough to handle this. Until then use Rollup which is proven and effective.

[ChristopherBiscardi]

Snowpack now produces esinstall, which is exactly what we need and is basically slimmed down snowpack v1