Use Entry in `yarn build ...` Instead of Label (#14148)

* Parse build script type and package names

This ensures that `yarn build core dom` includes DOM.

It also ensures that spaces like `yarn build "core, dom"` doesn't build EVERYTHING.

* Get rid of label in bundles config

Instead we just use the name from entry using fuzzy search.

There is one special case. If you put in `/index` or `/index.js`.

That allows to build things like `react/index` to only build isomorphic
where as `react` would build everything. Or `react-dom/index` to exclude
the server renderers.

* Instead of matching `/index.js` just append it to the search string

That way things like `yarn build react/` works too.