InspectorWidget, fix changing renderoptions when multiple objects are selected

modules/gfx/src/render_options/custom_render_options.cc

modules/gui/pymod/scene/cpk_widget.py

modules/gui/pymod/scene/custom_widget.py

modules/gui/pymod/scene/hsc_widget.py

modules/gui/pymod/scene/line_trace_widget.py

modules/gui/pymod/scene/simple_widget.py

modules/gui/pymod/scene/sline_widget.py

modules/gui/pymod/scene/trace_widget.py

modules/gui/pymod/scene/tube_widget.py