use proper RapidJSON API in qcnl

According to the way RapidJSON is used elsewhere in the repository (at e880e54c8f35d44a4763e08dff32a046c8ef2230), and how it is documented at `rapidjson.org`, the intended API appears to be:
```
#include
```
I think this change is required, and the additional RapidJSON related include need to be adjusted in the `Makefile`:
```patch
--- a/QuoteGeneration/qcnl/certification_provider.cpp
+++ b/QuoteGeneration/qcnl/certification_provider.cpp
@@ -36,7 +36,7 @@
*/
#include "certification_provider.h"
#include "certification_service.h"
-#include "document.h"
+#include
#include "local_cache.h"
#include "pck_cert_selection.h"
#include "qcnl_util.h"
--- a/QuoteGeneration/qcnl/inc/pccs_response_object.h
+++ b/QuoteGeneration/qcnl/inc/pccs_response_object.h
@@ -37,7 +37,7 @@
#define PCCSRESPONSEOBJECT_H_
#pragma once

-#include "document.h"
+#include
#include "qcnl_def.h"
#include
#include
--- a/QuoteGeneration/qcnl/inc/qcnl_config.h
+++ b/QuoteGeneration/qcnl/inc/qcnl_config.h
@@ -38,7 +38,7 @@
#pragma once

#include "sgx_default_qcnl_wrapper.h"
-#include "document.h"
+#include
#include
#include

--- a/QuoteGeneration/qcnl/linux/qcnl_config_impl.cpp
+++ b/QuoteGeneration/qcnl/linux/qcnl_config_impl.cpp
@@ -35,7 +35,7 @@
*
*/

-#include "istreamwrapper.h"
+#include
#include "qcnl_config.h"
#include
#include
--- a/QuoteGeneration/qcnl/qcnl_config.cpp
+++ b/QuoteGeneration/qcnl/qcnl_config.cpp
@@ -36,10 +36,10 @@
*/

#include "qcnl_config.h"
-#include "error/en.h"
-#include "error/error.h"
+#include
+#include
+#include
#include
-#include
#include
#include

```