This already revealed some places where implicit conversions were done, including some where its use was nonsense (MouseInput.cpp).
The changes to the Intent class were necessary to keep things working, and this splits things up more neatly.
`enabled_widgets` was used to enable input for widgets. However I do not recall anywhere this being used to specifically disable a widget which doesn't use the dedicated `disabled_widgets` flag. I don't think there is any purpose in keeping this, so I have removed all uses of it.
