chore(refactor): Create magicExports in Rollup build

[chaance]

This PR removes all magicExports modules from the source code and emits the files via Rollup instead. This eliminates any issues with TS or Node module resolution that will occur from copying the build output into a dist directory alongside the package source.

This will unblock #3540 which in turn will unblock the work needed to implement Changesets.

[brophdawg11]

The only thing I notice on a quick diff of a dev build/ versus here is these 2 lines are missing at the top of the generated files in this branch. We don't need use strict - but unsure if the __esModule is relevant for anything in the bundle landscape or just rollup cruft though

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });