OO-990: mostly fix of the authoring GUI, and unit tests, integrate the demo course to the test resource

OO-990: remove ControllerFactory, RepositoryEntryContext ( must be CourseSiteContext in every case), allow opening an editor by REST URL...

OO-990: rework importation of course node with references, implement autowiring capabilities in controllers

Merge OpenOLAT default branch to OpenOLATpro default branch  with 9a5d02062c328f6ab31aae75d02e7170c81fb459

OO-1069: round of optimizations, escape the & character, async reload the list of courses, groups and shared folders...

OO-1075: force the group by for all databases but MySQL (it's the only DB where the group by is case insensitive)

OO-716: fix multiple choice stats in survey, there is no wrong answer there but the QTI return 1 point for the first response and 0 for the next, remove the empty responses from the stats of essay

OO-1083: check if the 2 objects are of the same class before compare them with the generic compareTo method