OO-623: check more places where authors can create groups as enrolment and contact course building block, visibility access rules and course preview form

OO-609: if the evaluation raise an error, denied access instead of red screen and log the condition, it's not the fault of the user

OO-522: this fix the most obvious issue with a course that takes too long to load and an impatient user

OO-502: move the groups / roles cache from the RunMainController to the UserCourseEnvironment to speed-up the condition interpreter on course with a lot of rules