refactor the action info tab/API to allow for flows monitoring

For large usage of Anaplan (multiple data hubs and models), it is important to monitor the flows between models.

Anaplan is the ideal tool for that but currently many of the necessary info is not readily available.

The first and foremost thing to do is to set the API so that the imports endpoind of a model actually gives the source ID/source label for that import.

For conveniency, also include the Model GUID for each import in the JSON so it can be re-imported into Anaplan.