Additional fields (claims?) needed in GoogleJsonWebSignature.cs's Payload class

[hoekma]

JWT data is missing in the Payload instance returned from GoogleJsonWebSignature.ValidateAsync(). This is available in other languages' APIs based on this Google tutorial.

In a forked copy of the Google.Apis.Auth.GoogleJsonWebSignature, the following code in Google.ApisAuth.GoogleJsonWegbSignature.Payload class surfaced the missing data from the JWT, namely email, email_verified, name, picture, given_name, family_name, locale

Here is a link to a gist of my new Payload class' code :

https://gist.github.com/hoekma/7afa5444098a863d240ea2881e08bd53

P.S. I'm a little new to GitHub so let me know if there is a more appropriate way to suggest this.

[chrisdunelm]

Need to make sure all "claims_supported" from https://accounts.google.com/.well-known/openid-configuration are made available.