simplify right-side shortcuts impl, add gamecard and themezer to shortcut list, fix l2/r2 using wrong icons, sort l2/r2 so l2 displays first.

some other changes:
- shorten the next page and prev page to just next/prev in themezer.
- remove misc shortcut name. the function itself still exists.

sphaira/include/ui/menus/gc_menu.hpp

@@ -46,6 +46,7 @@ struct Menu final : MenuBase {
     auto GetShortTitle() const -> const char* override { return "GC"; };
     void Update(Controller* controller, TouchInfo* touch) override;
     void Draw(NVGcontext* vg, Theme* theme) override;
+    void OnFocusGained() override;
 
 private:
     Result GcMount();