Various cleanups and fixes: - Add InstancedDebugDraw properly to the Main Camera Prefab instead of adding it from code. - Remove FastDebugLine from always included shaders, utilising shader variant stripping. - Add material(s) to ensure line shader is included in builds. - Work around Unity quirk: Can't set shader commands from material property blocks. - Add a define to avoid matrix packing for easily confused GPU drivers. - Clean up shader properties and exposed the actual distance for distance fade. - Expose _Color, _LineWidth, _DistanceFade and _TransformType for potential use without instancing.