Create a global event before the rendering of a component or a widget

Hubl would like to use their own translation system, so they can translate the whole app with the same custom module.

For this, they would need a reliable way to translate the attributes of any component or widget before it renders.
To achieve this, we could have:

• an event. It would need to bubble so we can listen to the body and not miss nested components
• a callback. Probably better for performances
• a i18n API?

@balessan @clement any opinion on this?

Requested by Hubl