learningCloud: Other improvements

Other improvements

• The propagation of groups, users and group-user relationships between NetexCloud and learningCloud has been improved to avoid out-of-sync issues that sometimes resulted in a user not being able to access their sprints when they had been enrolled through a group.
• The performance of the editions management screen has been improved, separating users who have been registered through a group from those who have been registered individually.
• Chinese and Czech languages have been added.