Enables the `bpy.ops.cycles.denoise_animation()` operator again and modifies it to support
temporal denoising with OptiX. This requires renders that were done with both the "Vector"
and "Denoising Data" passes.
Differential Revision: https://developer.blender.org/D11442
* Split render/ into scene/ and session/. The scene/ folder now contains the
scene and its nodes. The session/ folder contains the render session and
associated data structures like drivers and render buffers.
* Move top level kernel headers into new folders kernel/camera/, kernel/film/,
kernel/light/, kernel/sample/, kernel/util/
* Move integrator related kernel headers into kernel/integrator/
* Move OSL shaders from kernel/shaders/ to kernel/osl/shaders/
For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
