Core: Fix main.ts/preview.ts

[shilman]

Issue: #14095

What I did

Move @babel/register to core-common which is the library that implicitly uses it

self-merging @yannbf

How to test

After publish:

  867  yarn create react-app cra-ts-maints --template typescript
  868  cd cra-ts-main-ts
  869  npx sb@next init
  870  mv .storybook/main.js .storybook/main.ts
  871  yarn storybook