OO-2975: delete imported calendar after course, group and user deletion, implement a check every 10 runs to remove deprecated imported calendar, append the job to the scheduler

OO-2968: fill the title and short title independently of the assessment informations, add a fallback solution to the list to show the course title instead an empty title

OO-2866: check if the test is ended before resuming and some small chaanges to handle the case without NPE

OO-2790: implement persistence of panel open/close for QTI 2.1 and comment, disclaimer, results and asssessment documents