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/clangdiagnosticmanager.h

@@ -51,7 +51,7 @@ public:
     ~ClangDiagnosticManager();
 
     void processNewDiagnostics(const QVector<ClangBackEnd::DiagnosticContainer> &allDiagnostics,
-                               bool showTextMarkAnnotations);
+                               bool fullVisualization);
 
     const QVector<ClangBackEnd::DiagnosticContainer> &diagnosticsWithFixIts() const;
     QList<QTextEdit::ExtraSelection> takeExtraSelections();
@@ -88,7 +88,7 @@ private:
     std::vector<ClangTextMark *> m_clangTextMarks;
     bool m_firstDiagnostics = true;
     bool m_diagnosticsInvalidated = false;
-    bool m_showTextMarkAnnotations = false;
+    bool m_fullVisualization = false;
     QTimer m_textMarkDelay;
 };