Add support for drag/drop of calendar events within the same month

Browsers Please test on each of the supported browsers Test set up Log in as a user Go to the calendar (from the nav drawer) New events can be added by clicking the “new event” button Test single day event Create a user event in the calendar and note down the start time (e.g. 8am) Drag the event to another day within the same month Confirm that the event is now displayed on the day that you moved it to and is no longer shown on the original day Click the event name to open the summary and click “edit” Confirm that the start time for the event hasn’t changed but the date has Drag the event away and then back to the same day before dropping it Confirm that nothing happens when the event is dropped back in it’s original location Test multi day event Create a user event the has a multiple day duration (click the “more” button in the modal to show the duration options) Drag the event from any of the the days Confirm that as it’s being dragged each of the days that will be affected are highlighted, for example an event with a 3 day duration should highlight 3 days as it’s being dragged to show where the event will be changed Confirm that the highlight wraps to the next week if the duration of the event goes beyond the end of the week Confirm that the event is now displayed in the correct location after it’s been dropped Test repeat event Create an event that has at least one repeat (click the “more” button in the modal to show the repeat options) Each of the repeat events will be treated independently from one another so confirm that they behave in accordance with “Test single day event”. Note: this may not be the ideal behaviour but will be addressed in a follow up issue. Test event with no permission Log in as admin Go to the calendar and create a site event Confirm that you are able to drag the event Log in as a student View the calendar Confirm that you are not able to drag the site event Test event generated by activity Log in as a teacher Create an assignment activity Log in as a student Add a submission for the assignment Log in as the teacher Go to your calendar Confirm that you can see the grading event for the assignment Confirm that you can’t drag the event (because it was automatically generated by an activity)