Strict Boolean Form Field
A form field for a Boolean that forces the user to make a choice from a list of choices. **Use Case** You have a Yes/No question the user must answer, but they may answer it yes or no. You don't want to supply a default because your need to force the user to actively select their answer. If they do not select an answer, the field should raise a validation error, like "This field is required". Normal BooleanField logic is based on a "checkbox", which, when "required" is required to be checked. This logic assumes that an empty value is the same as False -- in fact, there is no way for validators to distinguish between the empty value and False. Based on excellent suggestion from Peter DeGlopper: https://stackoverflow.com/a/56677670/1993525
- form_field