Merge topic 'raytracing_positionallights_paraview' into paraview/release

af084bd3 Added release note for light widget path tracing
0a6e6b0f Added test for light widget
890c60e2 Support ray-traced rendering of light widget/representation
f60d1dc2 Support positional light attenuation with ray tracing

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Reviewed-by: Cory Quammen <cory.quammen@kitware.com>
Merge-request: !11757