0026940: Visualization, TKOpenGl - capping plane should be applied to connected struc...

0026940: Visualization, TKOpenGl - capping plane should be applied to connected structures

OpenGl_Structure::Render(), OpenGl_CappingAlgo::RenderCapping() - render
groups of instanced and this structure in the same manner
using ::renderGeometry() and ::renderClosedGeometry() instead of ::DrawGroups().
Skip capping algo for structures without groups of closed primitives.