Download thumbnails (#690)

Mastodon/Scene/Onboarding/PickServer/PickServerSection.swift

@@ -63,7 +63,13 @@ extension PickServerSection {
                 ]
             )
         }()
-      
+        if let proxiedThumbnail = server.proxiedThumbnail, let thumbnailUrl = URL(string: proxiedThumbnail) {
+            cell.thumbnailImageView.af.setImage(withURL: thumbnailUrl) { _ in
+                OperationQueue.main.addOperation {
+                    cell.thumbnailImageView.isHidden = false
+                }
+            }
+        }
         attribute.isLast
             .receive(on: DispatchQueue.main)
             .sink { [weak cell] isLast in

Mastodon/Scene/Onboarding/PickServer/TableViewCell/PickServerCell.swift

@@ -31,6 +31,8 @@ class PickServerCell: UITableViewCell {
         thumbnail.translatesAutoresizingMaskIntoConstraints = false
         thumbnail.backgroundColor = Asset.Colors.brand.color
         thumbnail.layer.cornerRadius = 8
+        thumbnail.contentMode = .scaleAspectFill
+        thumbnail.layer.masksToBounds = true
         return thumbnail
     }()
     
@@ -66,7 +68,8 @@ class PickServerCell: UITableViewCell {
     
     override func prepareForReuse() {
         super.prepareForReuse()
-        
+        thumbnailImageView.isHidden = true
+        thumbnailImageView.image = nil
         disposeBag.removeAll()
     }