This PR is part of a larger effort to migrate error messages to MDX and use App Router: https://github.com/vercel/front/pull/23459
This adds updated matching handle for the server to separate out the matching and executing of different route types e.g. page routes, API routes, and app routes. Co-authored-by: JJ Kasper <22380829+ijjk@users.noreply.github.com>