ConsumerHandler now stores correct Consumer UUID

Handler was storing the id of the Consumer, and not the UUID
when handling created/deleted events.
Fixed filters when looking up deleted consumers

- findByUuid could not use findByKey as it is looking for an ID object.
  Used a straight lookup instead.
- use 'owner.key' when filtering deleted consumers.
- added some tests around the curator.
- added some convenience methods to Consumer.
Rename method since the name no longer fits
Lookup active consumer uuids instead of deleted ones.
Pull uuid from correct event target