Nuxt wizard: create example API route and update example component

[inventarSarah]

If the Nuxt wizard can't create an example page to test the setup, it creates a SentryErrorButton component. The user can use the component to throw an error in the frontend. (Users with an example page can test frontend and backend)

It would be great to have the wizard also create an API route and have the component call the API so users can verify their setup on both ends.
(also see next.js wizard)

Related PR in the docs repo: getsentry/sentry-docs#13286