This is used in various packages, so clean it up and add it
to rollup.utils.js.

Takes a package name and a dest path. This way we can more eassily change the
layout and it will error out on package name typos or missing packages.

as is the case with font packages

Instead of hardcoding the paths of the node_modules directory we use the node-resolve
plugin of rollup to find the root of the corresponding JS package and calcucate a path from
there.

Resolving a package requires calling an async function, so we have to use await in the rollup config.
Luckily rollup supports configs wrapped in a promise, so we just have to wrap it in a function which returns
a promise.