Problem with widget: value of mono-valued choice list do not seem constrained in UI

[demeringo]

Bug description

The value of the status field is not enforced in UI (edition mode)

1. Not all predefined choices are displayed
2. User is able to provide an empty value
3. User is able to add a new tag (i.e. provide its own value that is not in the predefined list of the model).

To Reproduce

Edit the status field. You are able to add a new custom value before submitting the form.

Expected behavior

Authorize only in UI:

• Draft
• Boavizta reviewed
• Published
• Not to be listed

JSON OUTPUT

Additional context

The validation of the value of this field in CI (post form submission) is already managed by #126 #127