Completely specify initial conditions for DynamicPipeEnergyConservationCheck and DynamicPipeEnergyConservationCheck2

[casella]

The models

ModelicaTest.Fluid.TestComponents.Pipes.DynamicPipeEnergyConservationCheck
ModelicaTest.Fluid.TestComponents.Pipes.DynamicPipeEnergyConservationCheck2

do not have fully specified initial conditions. These should be added to make sure that the initialization problem is not tool-dependent. This is probably also the reason why the first of the two models currently fails in OpenModelica.