Make VariantReporting::Command::CreateReport use Genome::Process

This breaks the Trio wrapper, which needs some more refactoring before it can have Genome::Process integration.
It's a bit odd to me that the inputs to the Process don't necessarily have anything to do with the inputs to the workflow being run within it (and that our subclass of Process could therefore be used to run any workflow under the sun on any inputs).

It would be good if Process does not need to rely on goodwill to be properly associated with the results it produces.  (It might be difficult to enforce that in general!)