Create a SSO Plugin

[slifty]

We want a plugin that will allow the user to log in using Auth0.

This will be relevant: https://auth0.com/docs/libraries/lock/v11/configuration

[reefdog]

Woo woo!

So the first version of this is going to use the loginWithPopup() function that doesn't use/require a callback URL. I have no faith this will survive the transition to the BuildFire app context, but if it does, 🎉.

If that falls through on-device, then the plan is to explore loginWithRedirect(), where the callback URL is a BuildFire custom URL scheme that maps back into the plugin. (Here's Apple's iOS article about it although Android supports it as well.) BuildFire's docs and library are pretty opaque here, so I'll raise the issue with BuildFire support if we get there.