Blender Git Loki

Fix T73726: Workbench Closest Interpolation Artifacts

All textures in workbench are using linear interpolation. The fragment
shader modifies the uv coordinates to sample always in the center of a
texel. In rare conditions the GPU could sample an incorrect value due to
rounding errors making some rendering artifacts.

This patch skips the interpolation in the fragment shader to remove
these render artifacts.

Reviewed By: Cl�ment Foucault

Differential Revision: https://developer.blender.org/D7816