OIDC's registration request seems not fully implemented

[christophehenry]

It appears OIDC registration request is not fully implemented. Is particular, fields like client_name and client_name#<lang> are not implemented:

export type loginOptions = {
  callbackUri: string,
  popupUri: string,
  storage: AsyncStorage
}

All in all, only issuer, grant_types, redirect_uris, response_types and scope fields are supported.

I will open a PR this afternoon for that.