[cli] Bootstrap authentication from create-toolpad-app

[bharatkashyap]

• Closes Add CLI step for authentication #3861

Adds

• Authentication prompt questions to create-toolpad-app

To Do

• Bootstrap .env.local with empty secrets but valid keys
• Handlenextjs-pages router branch

Questions

• Instead of using strings to bootstrap files, create template folders for different scenarios and copy them based on user selection, instead of writing string content into files? This is what create-next-app does, and it seems to be more readable and maintanable.
  • Keep using strings for now; it might scale better versus creating separate folder for each permutation of initial selection, and plays better with the webcontainers demo

[Janpot]

I could see us make each of those into a common shape like:

interface File {
  content: string
}

type Template = (option: Options) => File

That way a template has input, and can also return metadata beyond content

[Janpot]

Let's do this