Back out "Back out "[RN][Fabric] Introducing LayoutableShadownode::getContentOriginOffset and use it in ScrollView""

Summary:
This diff reverts a revert of D22456266 (https://github.com/facebook/react-native/commit/0060b5de559cd9c785a2a2a6c66f58088fea4dd2) and fixes the reason why it was reverted. Reverted in D22532594 (https://github.com/facebook/react-native/commit/c0e7e1bd9cf050b4a77a20212603d3468826979c).

For reason why it was introduced in the first place, please refer to D22456266 (https://github.com/facebook/react-native/commit/0060b5de559cd9c785a2a2a6c66f58088fea4dd2).

Problem:
`includeTransform` was not taken into account when calculating offset.

I added a unit test covering this specific scenario.

Reviewed By: shergin

Differential Revision: D22763011

fbshipit-source-id: e7d88fc19608ad1a4c7b5e594a9cc48122a2799b

ReactCommon/fabric/components/scrollview/ScrollViewShadowNode.cpp

@@ -37,11 +37,9 @@ void ScrollViewShadowNode::layout(LayoutContext layoutContext) {
   updateStateIfNeeded();
 }
 
-Transform ScrollViewShadowNode::getTransform() const {
-  auto transform = ConcreteViewShadowNode::getTransform();
+Point ScrollViewShadowNode::getContentOriginOffset() const {
   auto contentOffset = getStateData().contentOffset;
-  return transform *
-      Transform::Translate(-contentOffset.x, -contentOffset.y, 0);
+  return {-contentOffset.x, -contentOffset.y};
 }
 
 } // namespace react