get https://api.ottolearn.io/v1/rest/Mastery.ListUserConcepts()
Returns a list of all assigned Concepts for a specified User's Topic. If a Topic has no assigned Concepts, an empty array is returned. Each Concept returned will contain the Concept Id, Topic Id, identifier, the Id of the associated image, the rank for sorting of concept itself and the sortChildrenBy value used to determine the sorting order of Concept's Activities. If a User ID is not provided then it will return the results for the authenticated User ID