Add test support for intrinsic sized nodes

Summary: This diff adds support for intrinsic sizing in generated tests. This is done by importing a testing font called "Ahem" which, as used, has an exact width and height of 10px for each character. Support has been added for C++, Java, and Javascript generated tests.

Differential Revision: D58307002

tests/generated/YGPaddingTest.cpp

@@ -5,12 +5,13 @@
  * LICENSE file in the root directory of this source tree.
  *
  * clang-format off
- * @generated SignedSource<<f1bb0b5643b1db2ff78e5c327f45f0f3>>
+ * @generated SignedSource<<a9811894ca1ca801583ca4a59b0d4c7e>>
  * generated by gentest/gentest-driver.ts from gentest/fixtures/YGPaddingTest.html
  */
 
 #include <gtest/gtest.h>
 #include <yoga/Yoga.h>
+#include "../util/TestUtil.h"
 
 TEST(YogaTest, padding_no_size) {
   const YGConfigRef config = YGConfigNew();