Fabric: Using ShadowView instad of ShadowNode inside AttributedString

Summary:
That's generally better because:
 * Avoids exposing ShadowNode to mounting layer;
 * Enables hashing and comparing the AttributedString based on actual meaningful data (not on just a pointer to ShadowNode).

Reviewed By: mdvacca

Differential Revision: D13205230

fbshipit-source-id: 7b79c1aad97b10d81e3faa10408be61b74f815cf

ReactCommon/fabric/attributedstring/AttributedString.cpp

@@ -18,12 +18,12 @@ using Fragments = AttributedString::Fragments;
 #pragma mark - Fragment
 
 bool Fragment::operator==(const Fragment &rhs) const {
-  return std::tie(string, textAttributes, shadowNode, parentShadowNode) ==
+  return std::tie(string, textAttributes, shadowView, parentShadowView) ==
       std::tie(
              rhs.string,
              rhs.textAttributes,
-             rhs.shadowNode,
-             rhs.parentShadowNode);
+             rhs.shadowView,
+             rhs.parentShadowView);
 }
 
 bool Fragment::operator!=(const Fragment &rhs) const {
@@ -90,11 +90,6 @@ SharedDebugStringConvertibleList AttributedString::getDebugChildren() const {
     auto propsList =
         fragment.textAttributes.DebugStringConvertible::getDebugProps();
 
-    if (fragment.shadowNode) {
-      propsList.push_back(std::make_shared<DebugStringConvertibleItem>(
-          "shadowNode", fragment.shadowNode->getDebugDescription()));
-    }
-
     list.push_back(std::make_shared<DebugStringConvertibleItem>(
         "Fragment",
         fragment.string,