Camera TextureFormat rework

ExtractedView::hdr has been moved to ExtractedCamera::hdr. Views do not have a notion of HDR, which is a camera-specific property. TextureFormat::bevy_default() and ViewTargets::TEXTURE_FORMAT_HDR are deprecated, please source your texture format from ExtractedView::target_format instead, and plumb it through your specialization keys. Similarly, ViewTarget::is_hdr was removed. Use ExtractedCamera::hdr to check this instead.