Error handling in setters/getters of smart fields

What is the feature?

When declaring smart fields, we should be able to show errors from get()/set() directly in the UI.
We can already do it in routes with

response.status(400).send(‘Error description’)

but we can’t do it from the smart fields declaration logic.

What problem does this solve for you?

Being able to give feedback on the errors to the user

Who else would be using this feature?

Regular users as well as developers could benefit from this