Improve error messages in OidcIdTokenValidator

[jgrandja]

When a validation check fails in OidcIdTokenValidator the error message returned only has invalid_id_token. We should provide more informative error messages to the user that may include the claim name/value in the error message.

[raphaelDL]

Hi Joe, I tried the next:

I added message descriptions, and grouped errors in two steps, required fields and violated rules. I think is easier if we report the user more errors at once. Or maybe am I missing something?

What do you think? Just let me know I'm happy to improve it