ProjectExplorer: Rename IncludePathType to HeaderPathType

It is the type used by the HeaderPath class, so reflect that in
the name.

I also considered to rename HeaderPath to IncludePath, but
that name is reflected in a lot of users, which would also need
to be adjusted for consistency. That would blow up the patch size
for little value IMHO.

Change-Id: I51421dbd3ab8b2874dc32fc82dc394c9b93ce5e9
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/plugins/cpptools/cppcompletionassist.cpp

@@ -1260,7 +1260,7 @@ bool InternalCppCompletionAssistProcessor::completeInclude(const QTextCursor &cu
     // Make completion for all relevant includes
     ProjectExplorer::HeaderPaths headerPaths = m_interface->headerPaths();
     const ProjectExplorer::HeaderPath currentFilePath(QFileInfo(m_interface->fileName()).path(),
-                                                      ProjectExplorer::IncludePathType::User);
+                                                      ProjectExplorer::HeaderPathType::User);
     if (!headerPaths.contains(currentFilePath))
         headerPaths.append(currentFilePath);