Eliminate netconf-config artifact

netconf-config hosts three components:

1. global-netconf-ssh-scheduled-executor (a ScheduledThreadPool)
2. global-netconf-processing-executor (a ThreadPool)
3. plus the thread factory to go with that

The first is solely used in netconf-nb, the second is used by netconf-topology (and singleton and call-home). This layout is wrong, as we do not have proper task isolation and we have this shared dependency for no good reason.

Eliminate this component by:

1. moving the ScheduleThreadPool to netconf-nb, ditching the dependency on controller in the process
2. creating dedicated thread pools for each of the topology applications with its own config, perhaps with some tooling provided by topology.spi

This will render the thread factory superfluous, as each pool will have its proper name.