ProjectExplorer: Implement RunConfiguration::do{Clone,Restore} in base

It's possible now.

Change-Id: I49ed73312aea1627a9543890431e2e379e3fb3ec
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h

@@ -77,7 +77,7 @@ signals:
     void scriptSourceChanged();
 
 private:
-    void initialize(Core::Id id);
+    void initialize(Core::Id id) override;
     bool fromMap(const QVariantMap &map) override;
 
     void changeCurrentFile(Core::IEditor* = 0);