Remove dependency on consumer.guestIds and use consumers/ID/guests instead
Description of problem:
We have deprecated the consumer.guestIds field from the consumer object. A separate API has been added at consumers/ID/guests to get the information about guests running on a particular consumer. This RFE is to request that Katello be updated to use the new API in place of the old embedded object. This will allow us reduce the database load for all consumer calls which do not have guests.