Fix radio field requiredness sensing

Problem/Motivation

Conditionally required state change on radio field field widgets are still marked complete.

Steps to reproduce

1. Add a field_gate Boolean checkbox field to a content type.
2. Add a List (text) or a 2nd Boolean field.
3. In form display, add a Tabs group.
4. Add a Tab containing these fields.
5. Change the widget for the List (text) or Boolean field to Checkbox/radio buttons.
6. Add a Conditional Field to Require the radio field when field_gate is checked.
7. Visit the add node form.
8. Check the Gate box.
9. Observe that the Tab is still marked complete even though the required radio options has nothing checked.

Proposed resolution

Ensure that required radio fields are picked up by the complete sensor.

Remaining tasks

TBD

User interface changes

TBD

API changes

TBD

Data model changes

TBD