GT-2833 - Handle visibility conditionals for buttons & paragraphs #300
Description
Lesson quizzes use conditional visibility (mostly Family Lesson) for buttons to show after a user selects an option in the quiz using state value. Currently the web renderer does not observe these visibility conditionals, so all of the content appears and would confuse users.
The results page for the quiz also uses these conditionals on paragraphs to show the correct content to the user based on the state value of the quiz answer they select.
There should be a "watchVisibility(state) { }" callback that can be used on a button object that will be called whenever visibility of the button changes, which then should be reflected by the button disappearing from the UI
This is the content spec for the invisible-if and gone-if logic. We mostly use gone-if, but we would want this ticket for fix both.