title: displaying a lot of gifs in collectionview
body: <p>In my app I want to show gifs from giphy. The fetching and everyting is no problem, but I don't know what's the best way to display for example all trending gifs. 
  I have a collectionview which should display all gifs with this code:</p>
  
  <pre><code>  func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -&gt; UICollectionViewCell {
      let cell = collectionView.dequeueReusableCell(withReuseIdentifier: GifChooserCell.cellIdentifier, for: indexPath) as! GifChooserCell
  
        let data = try! Data(contentsOf: gif.giphyURL)
        let image = FLAnimatedImage(animatedGIFData: data)
        cell.image.animatedImage = image
  
  
      return cell
    }
  </code></pre>
  
  <p>The problem is that this loads everything into RAM and the application is extremely slow. What's the best way to do this? Async? Lazy loading?</p>