Challenge now will not know their world, as it is not necessary.
Remove ICON type, as it is useless.
Rename Level to Other, as under it will be not only level things.
Rename slot to order, as it was weird that users could define slot but not order. Order is easier to understand and use.
ChallengesLevel now knows all their levels.
Each challenge level only will be for single world.
Rename some variables.
ChallengesPlayerData was just adapted with changes in challenges and level classes.
In previous code challenges level status holds information for next level. It is fixed now, and current implementation allows to get everything that is needed.
BONNe1704
Florian CUNY