triggers whenever a job changed its status
adds a job to the worker's queue and starts it automatically
the job to run
starts the next free job if no other is running.
destroys the Taskmanager if not needed anymore.
returns the first free job
returns a job by its id.
checks if job is already in the queue
job to check
removes a job from the queue and tries to start another
the job's id
Inline web worker that runs jobs asynchronously.