EARL manifest reporter should create unique test case per type of run

[sspeiche]

Currently it only references 1 test case, even though it may be used for various types of resources. Take for example GetResource, it is actually run 3 times for different kinds of resources (configurations). So we should separate those out with unique URIs. It would make sense to link them back to where it is defined.

Also, need to group based on kinds of conformance: for now, we can just have DC, BC and IC.