Re-add timeline context menus

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -336,6 +336,14 @@ extension TimelineViewController: UICollectionViewDelegate {
         }
     }
     
+    func collectionView(_ collectionView: UICollectionView, contextMenuConfigurationForItemAt indexPath: IndexPath, point: CGPoint) -> UIContextMenuConfiguration? {
+        return (collectionView.cellForItem(at: indexPath) as? TimelineStatusCollectionViewCell)?.contextMenuConfiguration()
+    }
+    
+    func collectionView(_ collectionView: UICollectionView, willPerformPreviewActionForMenuWith configuration: UIContextMenuConfiguration, animator: UIContextMenuInteractionCommitAnimating) {
+        MenuPreviewHelper.willPerformPreviewAction(animator: animator, presenter: self)
+    }
+    
     func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
         if isShowingTimelineDescription {
             removeTimelineDescriptionCell()

Tusker/Views/Status/TimelineStatusCollectionViewCell.swift

@@ -582,6 +582,17 @@ class TimelineStatusCollectionViewCell: UICollectionViewListCell, StatusCollecti
         return [UIDragItem(itemProvider: provider)]
     }
     
+    func contextMenuConfiguration() -> UIContextMenuConfiguration? {
+        guard let status = mastodonController.persistentContainer.status(for: statusID) else {
+            return nil
+        }
+        return UIContextMenuConfiguration {
+            ConversationTableViewController(for: self.statusID, state: self.statusState.copy(), mastodonController: self.mastodonController)
+        } actionProvider: { _ in
+            UIMenu(children: self.delegate!.actionsForStatus(status, sourceView: self))
+        }
+    }
+    
 }
 
 extension TimelineStatusCollectionViewCell: UIContextMenuInteractionDelegate {