[HT] Remove pcs_0 from file names.

ProcessLib/HT/Tests.cmake

...cosityThermalConvection_ts_149_t_50000000000_000000_0.vtu

...cosityThermalConvection_ts_149_t_50000000000_000000_1.vtu

...cosityThermalConvection_ts_149_t_50000000000_000000_2.vtu

...cosityThermalConvection_ts_149_t_50000000000_000000_3.vtu

Tests/Data/Parabolic/HT/ConstViscosity/square_5500x5500.prj

...ata/Parabolic/HT/FaultedCube/Ra_795_fault_bcgs_jacobi.prj

...aultedCube/ThermalConvection_ts_1_t_0.000000_expected.vtu

...nthetics/CoupledPressureParabolicTemperatureParabolic.prj

...ata/Parabolic/HT/SimpleSynthetics/IsothermalFluidFlow.prj

...ic/HT/SimpleSynthetics/IsothermalFluidFlowWithGravity.prj

...impleSynthetics/PressureDiffusionTemperatureDiffusion.prj

...impleSynthetics/PressureParabolicTemperatureParabolic.prj