Class to create the Data Upgrade for Quizzes.
- __construct — Protected constructor for class
- build_progress_output — Common function to build the returned data progress output.
- convert_user_meta_quizzes_progress_to_activity — Convert single user quiz attempts to Activity DB entries.
- process_upgrade_action — Class method for the AJAX update logic This function will determine what users need to be converted. Then the course and quiz functions will be called to convert each individual user data set.
- query_items — Common function to query needed items.
- show_upgrade_action — Show data upgrade row for this instance.