We had some circular imports in the build that were due to modules

referencing up to a parent module in order to get a type. Many of these

should arguably not be circular imports, but nonetheless, Rollup was

complaining.
We now consistently import using type ... wherever appropriate, rather

than importing everything normally. This helps Rollup handle the

references correctly.
There are still some legitimate circular imports between core/craft ->

core/paint -> core/craft, which is harder to solve. This isn't

preventing builds, just generating some major complaints in Rollup.

Compared the new builds vs. the old ones, and verified that there were

no actual changes in the built JavaScript, which is what we'd hope for

here.
Unit tests pass.