[docs] updated documentation for renamed classes

man/OGS6.Rd

man/OGS6_Chain.Rd

man/OGS6_Ensemble.Rd

man/OGS6_pvd.Rd

man/OGS6_vtu.Rd

man/examples/ex_prj_borehole_heat_exchanger.R

man/examples/ex_prj_boundary_condition.R

man/examples/ex_prj_capillary_pressure.R

man/examples/ex_prj_chemical_system.R

man/examples/ex_prj_com_property.R

man/examples/ex_prj_component.R

man/examples/ex_prj_constitutive_relation.R

man/examples/ex_prj_convergence_criterion.R

man/examples/ex_prj_curve.R

man/examples/ex_prj_deactivated_subdomain.R

man/examples/ex_prj_eigen.R

man/examples/ex_prj_flow_and_temperature_control.R

man/examples/ex_prj_fluid.R

man/examples/ex_prj_fracture_model.R

man/examples/ex_prj_fracture_properties.R