Limit batch_utils progress bar STDOUT output

[zwolf]

The batch_extract and batch_reduce functions within batch_utils module uses progressbar to estimate the time remaining and print them to STDOUT and cannot be turned off. The new batch aggregation feature uses this library and progressbar ends up printing thousands of lines to the worker logs, including the same number many times (depending on the speed of the action). It would be great if this could either be turned off or have the frequency that it prints lowered to something that wouldn't flood the logs quite so much.