examples.component.helix.MainContainer: add a view controller

this is a pretty old example and has inline logic which relies on the helix having a static id.

since we now want to use it inside the portal app LivePreview, we need to re-generate it as needed => we need dynamic ids and a better separation of concerns.

the good news is that there is already a better version out there: Covid.view.HelixContainer Covid.view.HelixContainerController