[keycloak-dev] Associate social account with IDM user

[Stian Thorgersen]

We need to be able to associate multiple social providers with an IDM user. At the moment this is not based on the username of the account (for example google.23897892sdf). This has to main drawbacks:

* Horrible username
* Can only associate a single social account with an IDM user

What is the best way to store this information? We mainly need to store what social providers a user has linked and the social userid. In the future we may also want to associate access tokens as well. We also need to lookup a user based on the social provider + social userid.