Dask local cluster not created if bulk management on worker service

If bulk management is fully delegated to bulk worker service, Dask back end is then not needed. The purpose of the changes is to prevent creation of Dask cluster in that case reducing memory footprint and unnecessary Dask scheduler.

Note: It also contains changes to address an issue when worker service is enabled. /version endpoint returns additional details regarding bulk management backend setup (either Dask or bulk worker service).