Fix T93418: Cycles shadow terminator Geometry Offset artifacts with translucency

Differential Revision: https://developer.blender.org/D13468

Fix T93418: Cycles shadow terminator Geometry Offset artifacts with translucency

Differential Revision: https://developer.blender.org/D13468

Fix T91064: Cycles low poly meshes having black edges when shade smoothed

Fixes:{T91064}

Caused by {rBcd118c5581f482afc8554ff88b5b6f3b552b1682}

- Applies `ensure_valid_reflection()` to the normal input on all BSDFs for CPU and GPU.
- This doesn't affect hair.
- Removes `ensure_valid_reflection()` from the output of Bump Map and Normal Map nodes for CPU/GPU as it is not needed.
- The fix doesn't touch OSL.

Reviewed By: brecht, leesonw

Maniphest Tasks: T91064

Differential Revision: https://developer.blender.org/D12403

Fix T90423: black pixels after shadow terminator geometry offset

Solves an error in the principled diffuse BSDF, where it was not correctly
rejecting directions outside the hemisphere.

Differential Revision: https://developer.blender.org/D12283

Cycles: reduce shadow terminator artifacts

Offset rays from the flat surface to match where they would be for a smooth
surface as specified by the normals. In the shading panel there is now a
Shading Offset (existing option) and Geometry Offset (new).

The Geometry Offset works as follows:
* 0: disabled
* 0.001: only terminated triangles (normal points to the light, geometry
doesn't) are affected
* 0.1 (default): triangles at grazing angles are affected, and the effect
fades out
* 1: all triangles are affected

Limitations:
* The artifact is still visible in some cases, it could be that some quads
require to be treated specifically as quads.
* Inconsistent normals cause artifacts.
* If small objects cast shadows to a big low poly surface, the shadows can
appear to be in a wrong place - because the surface moved slightly above
the geometry. This can be noticed only at grazing angles to light.
* Approximated surfaces of two non-intersecting low-poly objects can overlap
that causes off-the-wall shadows.

Generally, using one or a few levels of subdivision can get rid of artifacts
faster than before.

Differential Revision: https://developer.blender.org/D11065

EEVEE: Geometry info -> tangent: Make consistent with Cycles for hair

Changes output for geometry info node in Eevee to be consistent with Cycles (w/o osl)

Before this patch Eevee outputs Z-tangent even for hair. This patch changes it to output hair tangent (growth direction). Hair tangent is impossible to derive otherwise from normal or view direction.

Reviewed By: fclem, brecht
Differential Revision: https://developer.blender.org/D10841