[gui] intro: inform caller if intro was shown

src/qt/intro.h

@@ -46,7 +46,7 @@ public:
      * @note do NOT call global GetDataDir() before calling this function, this
      * will cause the wrong path to be cached.
      */
-    static bool pickDataDirectory(interfaces::Node& node);
+    static bool showIfNeeded(interfaces::Node& node, bool& did_show_intro);
 
 Q_SIGNALS:
     void requestCheck();