[#82] Replace sponza with PBR version

.../voxelization/resources/Sponza/Textures/Flagpole_Diff.jpg

.../voxelization/resources/Sponza/Textures/Flagpole_Norm.jpg

.../voxelization/resources/Sponza/Textures/Flagpole_Spec.jpg

...s/voxelization/resources/Sponza/Textures/Floor_A_Diff.jpg

...s/voxelization/resources/Sponza/Textures/Floor_A_Norm.jpg

...s/voxelization/resources/Sponza/Textures/Floor_A_Spec.jpg

...ts/voxelization/resources/Sponza/Textures/Flower_Diff.png

...ts/voxelization/resources/Sponza/Textures/Flower_Norm.jpg

...ts/voxelization/resources/Sponza/Textures/Flower_Spec.jpg

...ects/voxelization/resources/Sponza/Textures/Lion_Diff.jpg

...ects/voxelization/resources/Sponza/Textures/Lion_Norm.jpg

...ects/voxelization/resources/Sponza/Textures/Lion_Spec.jpg

...ects/voxelization/resources/Sponza/Textures/Roof_Diff.jpg

...ects/voxelization/resources/Sponza/Textures/Roof_Norm.jpg

...ects/voxelization/resources/Sponza/Textures/Roof_Spec.jpg

...ts/voxelization/resources/Sponza/Textures/Shield_Norm.jpg

...ts/voxelization/resources/Sponza/Textures/Shield_Spec.jpg

...ts/voxelization/resources/Sponza/Textures/Shield_diff.jpg

...cts/voxelization/resources/Sponza/Textures/Thorn_Diff.png

...cts/voxelization/resources/Sponza/Textures/Thorn_Norm.jpg