Function UIImageJPEGRepresentation

pub unsafe extern "C-unwind" fn UIImageJPEGRepresentation(
    image: &UIImage,
    compression_quality: CGFloat,
) -> Option<Retained<NSData>>

Available on crate features UIImage and objc2-core-foundation only.

return image as JPEG. May return nil if image has no CGImageRef or invalid bitmap format. compression is 0(most)..1(least)