Update Nhost Auth Examples to v2

[dthyresson]

See: redwoodjs/graphql#4357

With v2,

Hasura Backend Plus is replaced by Hasura Auth and Hasura Storage. The new authentication service is very similar to Hasura Backend Plus with one big difference; the users table has been moved to the auth schema and merged with the accounts table. This change was necessary to more easily release new features to Hasura Auth and for customers to track migrations separately from Hasura Auth.

One the PR above is complete, then can implement changes needed to demo.

cc @nunopato