Turbopack: add support for an assetPrefix and basePath (#56058)
Depends on vercel/turbo#6036
This constructs a general asset prefix (depending on if basePath and/or assetPrefix is defined), and sets it on Next's and Turbopack's chunking context.
Test Plan: Use a `create-next-app` with corresponding Next.js PR and basePath and assetPrefix specified.
Tested:
- Browser (async) chunk loading
- Static asset loading on server and browser
Closes WEB-1666
