Support no-default-exports workflows

[mrmckeb]

Describe the feature you'd like to request

Our style guide enforces import/no-default-export. We find this helps with TypeScript IntelliSense (auto-completion) in IDEs like VSCode.

Right now, Next.js requires default exports in pages and API routes.

Describe the solution you'd like

Where Next.js expects default exports today, we'd like the option of using named exports.

For example:

// pages/my-page.tsx

export function Page ()  { /* .. */ }

export async function getServerSideProps () { /* .. */ }

Describe alternatives you've considered

We could, as an alternative, disable this rule for anything in the pages directory (and in any other places it would be needed).