ui: project wizzard design

* switched to QGridLayout for wizzard content layouting
* distinguish scrollable windows based on content
* content can define window size
* removed QtApplicationSettingsScreen, now done via QtProjectWizzardWindow and QtProjectWizzardContentPreferences
* added new project icon

src/lib_gui/qt/window/QtMainWindow.h

@@ -97,7 +97,7 @@ public slots:
 	void activateWindow();
 
 	QtSettingsWindow* about();
-	QtSettingsWindow* openSettings();
+	void openSettings();
 	QtSettingsWindow* showLicenses();
 	QtSettingsWindow* enterLicense();