Blender Git Loki

Sculpt/Paint: Add Paint Studio Light preset

This studio light preset is designed for color painting tasks. As color
are multiplied on top of the current studio light/matcap, this should be
as white as possible and with very soft speculars to avoid color
distorsion while showing the volume of the mesh.

Reviewed By: jbakker, JulienKaspar

Differential Revision: https://developer.blender.org/D8209