Stop ignoring image swizzles on depth and stencil images.
This doesn't fix a known issue on Xenoblade Chronicles 2 where an OpenGL
texture changes swizzles twice before being used. A proper fix would be
having a small texture view cache for this like we do on Vulkan.
Reduces some header churn and reduces rebuilds when some header
internals change.
While we're at it we can also resolve a missing include in buffer_cache.
