[turbopack] Add `registerEntry()` to handle inline bootstrapping (#94664)
In https://github.com/vercel/next.js/pull/94631, we started pushing
items to `globalThis["TURBOPACK"]` that were of a slightly different
shape. See the comment on
https://github.com/vercel/next.js/pull/94631#issue-4626372740.
This PR adds a new method `registerEntry()` that is able to take that
new shape (the object without the file name as an argument) and still
instantiate the module + load the other chunks.