Return question file areas viewable by the user in mod_quiz Web Services

There are several Web Services that return the current state of a question/attempt but they are not returning in a structured way a list of files viewable by the user that are part of the question (question text, general feedback, question type-specific, etc...)

There are some challenges here, specifically to identify what files are viewable by the user and when (for example, feedback for answers files should be only returned when the user is able to see them because he already finished the quiz)