OpenCL Volume Convolve/Blur/Sharpen SOPs

OpenCL Volume Convolve SOP: Convolves a volume by a 3×3×3 kernel.

OpenCL Volume Blur SOP: Applies Gaussian blur to a volume.

OpenCL Volume Sharpen SOP: Sharpens the voxels of a volume using the unsharp mask technique that enhances edges via a procedure that subtracts a blurred version of the volume from the original volume.