Fix windows 4018 and 4244 compiler warnings (#41254)

Summary:
Windows had to remove some previously suppressed compiler warnings and fork `ShadowNode.cpp` and `RawPropsParser.cpp` (See: microsoft/react-native-windows#12300) to fix them. This PR adds the right data types and static casts to get rid of the compiler warnings.

## Changelog:

[GENERAL] [FIXED] - Fix windows 4018 and 4244 compiler warnings

Pull Request resolved: #41254

Test Plan: tested in RNW Repository

Reviewed By: rshest

Differential Revision: D50820705

Pulled By: rozele

fbshipit-source-id: fa61f7ca428d31fc6be56c80215246ee2bdfc67c

packages/react-native/ReactCommon/react/renderer/core/RawPropsParser.cpp

@@ -33,7 +33,7 @@ const RawValue* RawPropsParser::at(
     // 4950 lookups and equality checks on initialization of the parser, which
     // happens exactly once per component.
     size_t size = keys_.size();
-    for (int i = 0; i < size; i++) {
+    for (size_t i = 0; i < size; i++) {
       if (keys_[i] == key) {
         return nullptr;
       }
@@ -69,7 +69,8 @@ const RawValue* RawPropsParser::at(
   do {
     rawProps.keyIndexCursor_++;
 
-    if (UNLIKELY(rawProps.keyIndexCursor_ >= keys_.size())) {
+    if (UNLIKELY(
+            static_cast<size_t>(rawProps.keyIndexCursor_) >= keys_.size())) {
 #ifdef REACT_NATIVE_DEBUG
       if (resetLoop) {
         LOG(ERROR)

packages/react-native/ReactCommon/react/renderer/core/ShadowNode.cpp

@@ -243,7 +243,7 @@ void ShadowNode::replaceChild(
   auto& children = const_cast<ShadowNode::ListOfShared&>(*children_);
   auto size = children.size();
 
-  if (suggestedIndex != -1 && suggestedIndex < size) {
+  if (suggestedIndex != -1 && static_cast<size_t>(suggestedIndex) < size) {
     // If provided `suggestedIndex` is accurate,
     // replacing in place using the index.
     if (children.at(suggestedIndex).get() == &oldChild) {