refactor(nsview): use layoutSubtreeIfNeeded

Lay out the NSView hierarchy explicitly as described in pointfreeco#412

Author: tillhainbach

Sources/SnapshotTesting/Snapshotting/NSView.swift

@@ -31,6 +31,7 @@ extension Snapshotting where Value == NSView, Format == NSImage {
 
       let initialFrame = view.frame
       if let size = size { view.frame.size = size }
+      view.layoutSubtreeIfNeeded()
       guard view.frame.width > 0, view.frame.height > 0 else {
         fatalError("View not renderable to image at size \(view.frame.size)")
       }
@@ -72,11 +73,8 @@ extension Snapshotting where Value == NSView, Format == NSImage {
 
             }
 
-            // This is to maintain compatibility with `recursiveDescription` because the current
-            // test snapshots expect `.needsLayout = false` and for some apple magic reason
-            // `view.needsLayout = false` does not do anything, but this does.
-            let bitmapRep2 = view.bitmapImageRepForCachingDisplay(in: view.bounds)!
-            view.cacheDisplay(in: view.bounds, to: bitmapRep2)
+            // This is to maintain compatibility with `recursiveDescription`
+            view.layoutSubtreeIfNeeded()
           }
 
         }