"use server" breaks if export default used

[justinvdm]

When using "use server", you're able to export, but not export default. Otherwise you'll see this when you pnpm build

src/app/pages/invoice/routes.ts (3:7): "default" is not exported by "src/app/pages/invoice/ListPage/InvoiceListPage.tsx", imported by "src/app/pages/invoice/routes.ts".
file: /Users/justin/rw/reloaded/experiments/billable/src/app/pages/invoice/routes.ts:3:7

1: import { db, index, route } from "@redwoodjs/reloaded/worker";
2: import InvoiceDetailPage from "./DetailPage/InvoiceDetailPage";
3: import InvoiceListPage from "./ListPage/InvoiceListPage";

This happens because of how we transform "use server" modules to wrap exports to register server-side actions. We need to either fix this, or if it makes sense to keep the restriction, catch it and provide understandable error message about what happened, how to fix it, and why it needs to be that way.