changes in FS to get hierarchical view on a forumTopic, added a showcase sample

removed getForumReplies(topicUuid,parameters) method
and addded
-getReplies(params)
-getTopicReplies(topicUuid)
-getTopicReplies(topicUuid,params)
-getReplyReplies(replyUuid)
-getReplyReplies(replyUuid,params)

so that its easier for consumer to get hierarchical view for forum Replies, this is consistent with js version