Allow keyboard binding in nogui/fullscreen mode (#1679)

* Allow keyboard binding in nogui/fullscreen mode

src/frontend-common/fullscreen_ui.h

@@ -47,6 +47,7 @@ void OpenQuickMenu();
 void CloseQuickMenu();
 void Shutdown();
 void Render();
+bool HandleKeyboardBinding(const char* keyName, bool pressed);
 
 bool InvalidateCachedTexture(const std::string& path);