Question bank: Cannot edit questions if you don't have the 'question/move' capability

With 4.0, we removed the ability to change category while editing as questions which means we do not validate permission moodle/question:movemine and moodle/question:moveall when editing the question.

Note: this is not a common combination of options for Teachers using the question bank in standard Moodle, but it basically makes StudentQuiz un-usable by students. (SQ for Moodle 4.0 is being worked on now.)