Make all headers public and add #ifdef __cplusplus (#1150)

Summary:
This change is mostly needed to support the new react-native architecture with Swift. Some private yoga headers end up being included in the swift build and result in compilation failure since swift cannot compile c++ modules. See https://github.com/facebook/react-native/pull/33381.

The most reliable fix is to include all headers as public headers, and add `#ifdef __cplusplus` to those that include c++. This is already what we do for other headers, this applies this to all headers.

Tested in the YogaKitSample, and also in a react-native app.

Changelog:
[iOS] [Changed] - Make all Yoga headers public and add #ifdef __cplusplus

Pull Request resolved: https://github.com/facebook/yoga/pull/1150

Reviewed By: dmitryrykun

Differential Revision: D36966687

Pulled By: cortinico

fbshipit-source-id: a34a54d56df43ab4934715070bab8e790b9abd39

Yoga.podspec

@@ -1,8 +1,9 @@
-# Copyright (c) Facebook, Inc. and its affiliates.
+# Copyright (c) Meta Platforms, Inc. and affiliates.
 #
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
+
 Pod::Spec.new do |spec|
   spec.name = 'Yoga'
   spec.version = '1.14.0'
@@ -33,6 +34,6 @@ Pod::Spec.new do |spec|
       '-fPIC'
   ]
   spec.source_files = 'yoga/**/*.{c,h,cpp}'
-  spec.public_header_files = 'yoga/{Yoga,YGEnums,YGMacros,YGNode,YGStyle,YGValue}.h'
+  spec.public_header_files = 'yoga/*.h'
 
 end