Enable mutable configuration

As it stands, whenever changes are made to the Watcher configuration file all services need to be restarted in order to pick up the new configuration setup. In a real world environment, a user won't be dealing with services shutting down and spinning back up when some aspect of configuration gets changed. In order to stay consistent with this, constantly running services that can dynamically update as changes are made provides a much more realistic view of how user interact with services.

Link to the goal: https://governance.openstack.org/tc/goals/rocky/enable-mutable-configuration.html