Rename queue_type to worker_type and key_name to worker_name.
The different types of workers use queues, so 'worker type'
is more accurate than 'queue type'
The 'key_name' title used to describe a hash (array) key, but
it really is just the name of the worker, and sometimes the
worker type is combined with the worker name to get the actual
hash key
Rename queue_type to worker_type and key_name to worker_name.