Gamification Engine:

- service implementation:

	- created the service getRuleTemplateList for getting the list of ruleTemplates concerning a gamificationPlugin specified
	- created the related test for the service implemented
	- refactoring of RuleTemplate and related classes
	- various refactoring related to the LeaderboardPoint plugin and the mocks that manage it
	- added some todos to improve the configuration of the httpClient service test callers