Clang: Reduce diagnostic visualization for non-project files further

We already avoided showing inline annotations for diagnostics in
non-project files. But given many diagnostics the visualization is still
quite noisy. E.g. consider opening not self-contained header files or
files for which we do not have any project open, as it can happen if the
debugger jumps to such a file.

So leave only the text mark icon on the left and avoid all the rest:
underlines and refactoring icons in the editor, marks in the scrollbar
and task hub issues.

Change-Id: I05245981b21b38be650489a006593922dcb6896d
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangtextmark.h

@@ -42,7 +42,7 @@ public:
     ClangTextMark(const ::Utils::FileName &fileName,
                   const ClangBackEnd::DiagnosticContainer &diagnostic,
                   const RemovedFromEditorHandler &removedHandler,
-                  bool showLineAnnotations);
+                  bool fullVisualization);
 
     void updateIcon(bool valid = true);
 private: