can use Google client library for userinfo call

[tomholub]

Google library supports this request - https://github.com/google/google-api-objectivec-client-for-rest/blob/main/Source/GeneratedServices/Oauth2/GTLROauth2Query.m#L46

The only difference is that it uses oauth2/v2/userinfo instead of oauth2/v3/userinfo, but response looks similar.

Originally posted by @sosnovsky in #985 (comment)

[ivan-ushakov]

@tomholub May I start with 0.9.0: Post-EIS maintenance tasks?

[tomholub]

thanks for checking - yes you can go ahead and work on these