tests/texture: use projection and modelview matrices in texture_mipmap test shader
tests/texture: use projection and modelview matrices in texture_mipmap test shader

Makes the output of the shader compatible with the upcoming Vulkan
backend.

gopro/gopro-lib-node.gl,gopro/gopro-lib-node.gl,gopro/gopro-lib-node.gl,gopro/gopro-lib-node.gl