performance main thread

[Zhingel]

`func image(size: CGSize, resultClosure: @escaping (UIImage?)->()) -> PHImageRequestID {
let requestSize = CGSize(width: size.width * UIScreen.main.scale, height: size.height * UIScreen.main.scale)

    let options = PHImageRequestOptions()
    options.isNetworkAccessAllowed = true
    options.deliveryMode = .fastFormat

    return PHCachingImageManager.default().requestImage(
        for: self,
        targetSize: requestSize,
        contentMode: .aspectFill,
        options: options,
        resultHandler: { image, info in
            DispatchQueue.main.async {      // add this
                resultClosure(image) // called for every quality approximation
            } 
        }
    )
}`

and also don't use geometry reader for getting cell size, because it's kill performance too, you should got cell size from UIScreen.main.bounds