Updated existing logging for the worker api to be a bit more
consistent and added some additional logging.
In addition to the logging improvements the following changes
were also made.
- Replaced legacy endpoint zone_api with worker_api as
the zone api no longer exists.
- Merged mixing code with base class to simplify code.
Change-Id: Ie948931c1d31444c67829767f9ccb6c5eb6e6601
Erik Olof Gunnar Andersson
147e00f44f