fix: Ensure we're referencing up-to-date swipe state when configuring interaction enabled (#595)

For https://block.atlassian.net/browse/UI-9091

This resolves an issue where a cell would not respond to taps after the
"full swipe" swipe action trigger.

The issue was that we were referencing stale swipe state when
configuring `isUserInteractionEnabled`. It was quite unintuitive when
debugging this, but the line `swipeState = state` immediately resulted
in those variables holding different values while processing the swipe
action 🙃. We would incorrectly fall into the
`.willPerformFirstActionAutomatically` case, making the content view
unresponsive, despite the `swipeState` reporting as `.closed`.

The SwipeActionsViewController has also been updated to demonstrate this
is now working as expected.

### Checklist

Please do the following before merging:

- [ ] Ensure any public-facing changes are reflected in the
[changelog](https://github.com/square/Listable/blob/main/CHANGELOG.md).
Include them in the `Main` section.

Author: robmaceachern

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ### Fixed
 
+- Fixed an issue where a full swipe of a swipe action could result in the cell being temporarily unresponsive.
+
 ### Added
 
 ### Removed

Development/Sources/Demos/Demo Screens/SwipeActionsViewController.swift

@@ -333,6 +333,9 @@ final class SwipeActionsViewController: UIViewController  {
                 .inset(uniform: 16)
             }
             .accessibilityElement(label: "Swipeable Item", value: item.title, traits: [.button])
+            .tappable {
+                print("Tapped \(item.title)")
+            }
         }
     }
 

ListableUI/Sources/Internal/ItemCell.ContentViewContainer.swift

@@ -286,8 +286,11 @@ extension ItemCell {
         private func set(state: SwipeActionState, animated: Bool = false) {
             swipeState = state
 
+            // Warning! : `swipeState` may be mutated to a new value via it's property
+            // observers and may not equal `state` at this point!
+
             // We don't want any actions on the content view while our swipe actions are open.
-            self.contentView.isUserInteractionEnabled = switch state {
+            self.contentView.isUserInteractionEnabled = switch swipeState {
             case .closed:
                 true
             case .expandActions, .open, .swiping, .willPerformFirstActionAutomatically: