Support Easy Auth on App Service

[isaacabraham]

I've found a few links lying around, such as this.

However, we also have to give consideration to the App Registration - 99/100 times this will be required to be created at the same time as activation of the easy auth, yet it should be created in an idempotent fashion.

[isaacabraham]

@ninjarobot are there any docs that you're aware of on the difference between authsettings and authsettingsv2?

https://docs.microsoft.com/en-us/azure/templates/microsoft.web/sites/config-authsettingsv2

Note that the schema in this doc doesn't match that used in the SO article above - e.g. there's no such field called issuer in the doc.

What should we be using etc. - are there any good examples out there that you know of (or someone that we can reach out to)?