Move document checking to a C++ header file

* It's better to edit C++ source natively not in the SWIG file, and also
  clang-format can format it.

qrenderdoc/qrenderdoc.pro

@@ -210,6 +210,8 @@ HEADERS += Code/CaptureContext.h \
     Code/QRDUtils.h \
     Code/Resources.h \
     Code/pyrenderdoc/PythonContext.h \
+    Code/pyrenderdoc/pyconversion.h \
+    Code/pyrenderdoc/document_check.h \
     Code/Interface/QRDInterface.h \
     Code/Interface/CommonPipelineState.h \
     Code/Interface/PersistantConfig.h \