HackStudio: Use a visually distinct icon for the cursor tool

Using the default cursor bitmap as the cursor tool icon in HackStudio
was predictably making it impossible to tell if it's the real cursor
or not. Replace it with a color-inverted cursor. :^)

DevTools/HackStudio/main.cpp

@@ -128,7 +128,7 @@ int main(int argc, char** argv)
     auto form_widgets_toolbar = GToolBar::construct(Orientation::Vertical, 26, g_form_inner_container);
     form_widgets_toolbar->set_preferred_size(38, 0);
 
-    form_widgets_toolbar->add_action(GAction::create("Cursor", GraphicsBitmap::load_from_file("/res/cursors/arrow.png"), [&](auto&) {
+    form_widgets_toolbar->add_action(GAction::create("Cursor", GraphicsBitmap::load_from_file("/res/icons/widgets/Cursor.png"), [&](auto&) {
     }));
 
     GWidgetClassRegistration::for_each([&](const GWidgetClassRegistration& reg) {