Merge CppTools into CppEditor

There was no proper separation of responsibilities between these
plugins. In particular, CppTools had lots of editor-related
functionality, so it's not clear why it was separated out in the first
place.
In fact, for a lot of code, it seemed quite arbitrary where it was put
(just one example: switchHeaderSource() was in CppTools, wheras
switchDeclarationDefinition() was in CppEditor).
Merging the plugins will enable us to get rid of various convoluted
pseudo-abstractions that were only introduced to keep up the artificial
separation.

Change-Id: Iafc3bce625b4794f6d4aa03df6cddc7f2d26716a
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/autotest/itestparser.h

@@ -28,7 +28,7 @@
 #include "testtreeitem.h"
 
 #include <cplusplus/CppDocument.h>
-#include <cpptools/cppworkingcopy.h>
+#include <cppeditor/cppworkingcopy.h>
 #include <qmljs/qmljsdocument.h>
 
 #include <QFutureInterface>
@@ -98,7 +98,7 @@ public:
 
 protected:
     CPlusPlus::Snapshot m_cppSnapshot;
-    CppTools::WorkingCopy m_workingCopy;
+    CppEditor::WorkingCopy m_workingCopy;
 };
 
 } // namespace Autotest