Information about unused interactions

[Fiszcz]

Is your feature request related to a problem? Please describe.
As a developer and a maintainer of some microservices I would like to get some additional data about my interactions between services.
For example when I create backend microservices using the REST API, it would be great if I can see which of my interactions are not being used by any of consumers (and probably after that this gives us information if there is a place in the code to refactor and remove unnecessary functions/functionalities).

Describe the solution you'd like
I think that Judge'd should return information about which of interactions are not used at all.

Describe alternatives you've considered
Probably we could also add information to interaction data about target consumers.

Additional context
It would be great to see this type of warnings in an implemented UI application of Judge'd.