I was very confused about the 2 interfaces
ILocalizable
ILocalized
There are 2 differences between them:
Difference 1: one is for widgets, the other for components
Difference 2: one is called to ask the recipient to do its localization on its own, the other is called _after_ this has happened.

We should in future unify the 2 into just "ILocalizable".

Until then, to make the difference clearer, I renamed them to
ILocalizableWidget
ILocalizableComponent