Automated setup of SSO config for tenants

Currently, there is no documented and supported API to setup SSO. The only supported way to update the SSO config is through the UI. The UI writes the configuration into a json object. The challenge with this approach is that as soon as we change the structure of this object we cannot guarantee backward compabitility anymore. One solution to solve this is to implement a microservice who does the abstraction between a well-defined API and the configuration stored within Cumulocity.