[Added] .custom case to MessageStyle to customize via closure

Example/Sources/ConversationViewController.swift

@@ -222,6 +222,8 @@ extension ConversationViewController: MessagesDisplayDelegate {
     func messageStyle(for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> MessageStyle {
         let corner: MessageStyle.TailCorner = isFromCurrentSender(message: message) ? .bottomRight : .bottomLeft
         return .bubbleTail(corner, .curved)
+//        let configurationClosure = { (view: MessageContainerView) in}
+//        return .custom(configurationClosure)
     }
 
     func messageFooterView(for message: MessageType, at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> MessageFooterView? {

Sources/MessageContainerView.swift

@@ -69,6 +69,11 @@ open class MessageContainerView: UIImageView {
             mask = nil
             image = nil
             tintColor = nil
+        case .custom(let configurationClosure):
+            mask = nil
+            image = nil
+            tintColor = nil
+            configurationClosure(self)
         }
     }
 

Sources/MessageStyle.swift

@@ -69,6 +69,7 @@ public enum MessageStyle {
     case bubbleOutline(UIColor)
     case bubbleTail(TailCorner, TailStyle)
     case bubbleTailOutline(UIColor, TailCorner, TailStyle)
+    case custom((MessageContainerView) -> Void)
 
     // MARK: - Public
 
@@ -79,7 +80,7 @@ public enum MessageStyle {
         guard var image = UIImage(contentsOfFile: path) else { return nil }
 
         switch self {
-        case .none:
+        case .none, .custom:
             return nil
         case .bubble, .bubbleOutline:
             break
@@ -103,7 +104,7 @@ public enum MessageStyle {
             return "bubble_full" + tailStyle.imageNameSuffix
         case .bubbleTailOutline(_, _, let tailStyle):
             return "bubble_outlined" + tailStyle.imageNameSuffix
-        case .none:
+        case .none, .custom:
             return nil
         }
     }