Seems like playCanvas doesn’t have a similar idea to Unity3D prefab, so I decided to make myself something as close as I could get it to be. But, why not share it =)
https://playcanvas.com/project/706598/overview/preparecloner
The basic idea is to have your assets ready in current scene or other scene and create clones out of it.
Let me know if it is helpful and if you need help with it.