Mark NS_SWIFT_UI_ACTOR for IGFeedItem cells and other protocols

Summary:
Mark `NS_SWIFT_UI_ACTOR` for IGFeedItem cells and other protocols.

In order to unblock D60809973, I need to update all these which is error triggered by enabling strict concurrency on Swift 6.

It's a trail and error and fix process, seem details inline.

Differential Revision: D61847332

fbshipit-source-id: 04909647da435c97875b10b3649d923c0b50bb76

Source/IGListKit/IGListAdapterDelegate.h

@@ -14,6 +14,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  Conform to `IGListAdapterDelegate` to receive display events for objects in a list.
  */
+NS_SWIFT_UI_ACTOR
 NS_SWIFT_NAME(ListAdapterDelegate)
 @protocol IGListAdapterDelegate <NSObject>