debugger: fixes and improvements related to the Locals display

Split the concepts 'enabled' and 'editable' in the dumper output
Disable "<not in scope>" entries, also fix their type.
Fix glitch in type beautification for display
Find reason for failing bulk updates.

src/plugins/debugger/watchwindow.h

@@ -64,6 +64,7 @@ private:
     Q_SLOT void resetHelper();
     Q_SLOT void expandNode(const QModelIndex &idx);
     Q_SLOT void collapseNode(const QModelIndex &idx);
+    Q_SLOT void setUpdatesEnabled(bool enable);
 
     void keyPressEvent(QKeyEvent *ev);
     void contextMenuEvent(QContextMenuEvent *ev);