This allows a duplicator (as known as dupli parent) to be in a visible
collection so its duplicated objects are visible, however while being
invisible for the final render.
An object that is a particle emitter is also considered a duplicator.
Many thanks for the reviewers for the extense feedback.
Reviewers: sergey, campbellbarton
Differential Revision: https://developer.blender.org/D2966
b89f2276e5