CppTools: Move RawProjectPart to ProjectExplorer

Doesn't have any dependencies into CppTools anymore, therefore moving it
reduces the dependencies of the project managers to CppTools as well.

Change-Id: Ibe728abe59eb88a8877943dca1f48a85163e27ac
Reviewed-by: hjk <hjk@qt.io>

src/plugins/cpptools/cpptools.pro

@@ -54,7 +54,6 @@ HEADERS += \
     cppprojectfile.h \
     cppprojectupdater.h \
     cppqtstyleindenter.h \
-    cpprawprojectpart.h \
     cpprefactoringchanges.h \
     cpprefactoringengine.h \
     cppselectionchanger.h \
@@ -155,7 +154,6 @@ SOURCES += \
     cppprojectfile.cpp \
     cppprojectupdater.cpp \
     cppqtstyleindenter.cpp \
-    cpprawprojectpart.cpp \
     cpprefactoringchanges.cpp \
     cpprefactoringengine.cpp \
     cppselectionchanger.cpp \