CureAction constructor should throw exception when the given character can't cure

[palra]

https://github.com/palra/univ-mmorpg/blob/feature/serialization/src/main/java/fr/univdevs/mmorpg/engine/action/CureAction.java

CureAction should accept only Characters that implements CanCure. The same with FightAction and CanFight. It should check it at the constructor, and associated exception should be created in the skills package

• [ ] CureAction(), CanCure
• [ ] FightAction(), CanFight

[drattak]

Skill package deleted