Native bindings to the EXT_texture_format_sRGB_override extension.

This extension provides a new texture parameter to override the internal format of a texture object; allowing a non-sRGB format to be overridden to a corresponding sRGB format. For example, an RGB8 texture can be overridden to SRGB8. Such an override will cause the RGB components to be "decoded" from sRGB color space to linear as part of texture filtering. This can be useful for applications where a texture was written with sRGB data using EXT_sRGB_write_control or when sampling from an EGLImage that is known to contain sRGB color values.