[SSR] Restrict exports from `lwc` package

[nolanlawson]

Follow-up to https://github.com/salesforce/lwc/pull/4617/files#r1800044756.

If you can't import certain things from 'lwc', then you shouldn't be able to export them either:

export { foo } from 'lwc'

Also we should probably rename allowedLwcImports to ssrFriendlyLwcImports or something, since that's the real intent.

[git2gus]

This issue has been linked to a new work item: W-16984771