Function: Queries the post listing data based on the user selections in the admin.

Function: Adds the assigned lesson & assigned course columns for topics and assignments in the admin.

Function: Adds the status and points columns for assignments in the admin.

Function: Removes the tags column for quizzes.

Function: Removes the categories column for quizzes.

Function: Outputs approval status for assignment in admin posts listing.

Function: Outputs the values for assigned courses in admin columns for lessons, quizzes, topics, and assignments.

Function: Outputs the select dropdown before the filter button to filter post listing by course.