[Coupling] Replaced the type of Process::_coupling_term, weak_ptr, with a

ProcessLib/ComponentTransport/ComponentTransportProcess.cpp

ProcessLib/GroundwaterFlow/GroundwaterFlowProcess.cpp

ProcessLib/HT/HTProcess.cpp

ProcessLib/HeatConduction/HeatConductionProcess.cpp

ProcessLib/HydroMechanics/HydroMechanicsProcess-impl.h

ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess.cpp

ProcessLib/LIE/HydroMechanics/HydroMechanicsProcess.h

ProcessLib/LIE/SmallDeformation/SmallDeformationProcess.h

ProcessLib/LiquidFlow/LiquidFlowProcess.cpp

ProcessLib/LocalAssemblerInterface.cpp

ProcessLib/LocalAssemblerInterface.h

ProcessLib/PhaseField/PhaseFieldProcess.h

ProcessLib/Process.cpp

ProcessLib/Process.h

ProcessLib/RichardsFlow/RichardsFlowProcess.cpp

ProcessLib/SmallDeformation/SmallDeformationProcess-impl.h

ProcessLib/TES/TESProcess.cpp

...alTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPProcess.cpp

ProcessLib/ThermoMechanics/ThermoMechanicsProcess.h

ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPProcess.cpp