Popup Menu Input Component

This task focuses on adding a popup menu to configure tower settings, which should be able to disappear if the mouse is clicked outside the window.

The method touchDown() is responsible for triggering a popupEvent that is able to toggle the menu.

The following UML explains the working of this event: The touchDown method in popupMenuInputComponent gets the entity the component is attached to (using functionality from the Component class), gets the event handler of that entity, and uses the event handler to trigger an event. This can potentially be used by another component of that entity to toggle the popup menu on or off, although other components for the popup menu entity have not been implemented as of sprint 1.