Refactor the Authentication Patterns in Realm JS

[sync-by-unito[bot]]

Authentication in Realm is wrapped in nested namespaces, which makes the process not entirely straightforward. I believe we should rethink the way authentication is done and come up with a more ergonomic interface.

For example:

// login
  const creds = Realm.Credentials.emailPassword(email, password);
  await app.logIn(creds);

// register
 await app.emailPasswordAuth.registerUser({email, password});

In most cases, all required parameters for authentication are nested. Perhaps something like:

import {emailPassword} from '@realm/auth'

emailPassword.login()
emailPassword.register()

[takameyer]

I believe that:

await app.emailPassword.registerUser({email, password});

Is a bit ambiguous. I would like to rethink the entire authentication flow to be more ergonomic and break it even more than just renaming some parts of it.