Optimize lighting.glsl and test.frag/.vert

[EclipsedMango]

Things to improve / optimize:
lighting.glsl:

• Move the rotation sampling in PointShadow and ShadowCalculation out of the loops.
• Reduce branching problem, maybe set the textures to like 1x1 white pixel if they dont exist.
• Move some of the Clustered index math to the cpu, like the zLog var.

test.frag/.vert:

• TBN percision, maybe only pass the tangent and normal and reconstruct bitangent in frag shader.