Merge branch 'bhe_weighting_factor' into 'master'

...rocesses/process/HEAT_TRANSPORT_BHE/t_weighting_factor.md

...essLib/HeatTransportBHE/CreateHeatTransportBHEProcess.cpp

ProcessLib/HeatTransportBHE/HeatTransportBHEProcess.cpp

...Data/Parabolic/T/3D_BHE_Sandwich/sandwich_algebraicBC.xml

...Parabolic/T/3D_BHE_Sandwich/sandwich_algebraicBC_LSCG.xml

...ic/T/3D_BHE_Sandwich/sandwich_fixed_power_algebraicBC.xml

...3D_BHE_Sandwich/sandwich_fixed_power_algebraicBC_LSCG.xml

...arabolic/T/3D_Beier_sandbox/beier_sandbox_algebraicBC.xml

...lic/T/3D_Beier_sandbox/beier_sandbox_algebraicBC_LSCG.xml

...D_Beier_sandbox/fixed_power_constant_flow_algebraicBC.xml

...er_sandbox/fixed_power_constant_flow_algebraicBC_LSCG.xml