Tweaks to Guardians and Elder Guardian

Originally the sponge drop from the Elder Guardian was a place holder item for a different treasure drop. Elder Guardians Should instead drop the Heart Of The Sea item, Also wet sponges should be a rare drop from Guardian when killed by a player or Axolotl. Additionally If a Guardian is struck by lightning then it should turn into an elder Guardian (potentially with a tag that makes the Heart Of The Sea only drop on random chance when killed). This change would make the Heart Of The Sea an item that is renewable but not farmable, While making sponges renewable and farmable but not easily. Granting Players grater access to technical blocks that are less popular otherwise.