[utils][management][commands][broker] Fix name handling

The callbacks receive the name of the worker as bytes,
convert them to string in order to be able to properly
filter the database content.
1 job for fix_broker_callbacks in 15 minutes and 26 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #209931
docker-build
build_linux_36

00:15:26

69.0%