Pagified ViewNotificationsCommand
- Users can use the 'length' and 'page' attributes to specify the number of elements per page and which page to look at
- Notifications are sorted by ID number for a naive chronological ordering
- Extracted interface of Notifications so that the JSP can deal with a singular list of Notifications rather than treat each one separately
- The NotificationType enums now have a helper method to get a lowercase version of their toString()