Add pointer effect to custom alert actions

Closes #306

Tusker/Screens/Utilities/CustomAlertController.swift

@@ -394,6 +394,8 @@ class CustomAlertActionButton: UIControl {
             self.isContextMenuInteractionEnabled = true
             self.showsMenuAsPrimaryAction = action.handler == nil
         }
+        
+        addGestureRecognizer(UIHoverGestureRecognizer(target: self, action: #selector(hoverRecognized)))
     }
     
     required init?(coder: NSCoder) {
@@ -429,6 +431,17 @@ class CustomAlertActionButton: UIControl {
         super.contextMenuInteraction(interaction, willEndFor: configuration, animator: animator)
     }
     
+    @objc func hoverRecognized(_ recognizer: UIHoverGestureRecognizer) {
+        switch recognizer.state {
+        case .began, .changed:
+            backgroundColor = .secondarySystemFill
+        case .ended:
+            backgroundColor = nil
+        default:
+            break
+        }
+    }
+    
     override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
         super.touchesBegan(touches, with: event)