Make the Interpreter be able to handle SimulatorTransport as well. This
includes introducing changes that make it possible to use the different
transport types in a semi-polymorphic way with the introduction of
factory methods in the RequestRouter. The reason for this solution is
that the classes that represent the different transport types have
member function templates, that we can not make virtual. This solution
seemed to be the least convoluted. In the testing itself now it is
possible to pass a set of cypher queried to the interpreter which would
run these queries against the interpreter and the individual shards that
are managed and started up by the MachineManager with the different
entities communicating over the simulated network.
This PR adds support for generating randomized workloads that will be executed
against a simulated cluster, as well as against a correctness model. Initially
this just generates ScanAll and CreateVertex requests, and anything that it
creates, it also inserts into a `std::set`, and when we do a ScanAll, it asserts
that we get the same number of requests back. This will become much more
sophisticated over time, but it's already hitting pay-dirt.
