Move core/include/fxcrt to core/fxcrt/include.

This CL moves the fxcrt code into the core/fxcrt directory. The only exception
was fx_bidi.h which was moved into core/fxcrt as it is not used outside of
core/.

R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1825953002 .
diff --git a/fpdfsdk/javascript/PublicMethods.cpp b/fpdfsdk/javascript/PublicMethods.cpp
index 6097369..b85111b 100644
--- a/fpdfsdk/javascript/PublicMethods.cpp
+++ b/fpdfsdk/javascript/PublicMethods.cpp
@@ -10,7 +10,7 @@
 #include <string>
 #include <vector>
 
-#include "core/include/fxcrt/fx_ext.h"
+#include "core/fxcrt/include/fx_ext.h"
 #include "fpdfsdk/include/fsdk_mgr.h"  // For CPDFDoc_Environment.
 #include "fpdfsdk/include/javascript/IJavaScript.h"
 #include "fpdfsdk/javascript/Field.h"