Move selection ring OverlayTexture code from CCmpSelectable::UpdateTexturedLineOverlay to the SOverlayTexturedLine struct in graphics/Overlay.cpp and SimRender in simulation2/helpers/Render.cpp.
This abstraction allows calling that code again from other simulation components, like the RangeOverlayRenderer in D555.
Differential Revision: https://code.wildfiregames.com/D1139
Refs #3915, D555
Comments By: Vladislav, echotangoecho