Use real identity provider locally

**Is your feature request related to a problem? Please describe.**
When developing locally, I cannot test my application against a real identity provider using the static web apps CLI.

**Describe the solution you'd like**
I would like to have the option to use the mock authentication interface or a real provider.

**context**
I want to be able to turn off this interface and use auth0 locally.
[auth0 mock interface image](https://ibb.co/X4w2CQy)

Start with issue #447 and its request to switch between the mock authentication interface and Auth0 when running the CLI locally. Done means local development can select either authentication mode and use a real identity provider without losing the existing mock option.

Written by the indexing model from the issue text.