In all cases (oss/ent, client/server) this method was returning a value from config. Since the
value is consistent, it doesn't need to be part of the delegate interface.
* Implement leader routine manager
Switch over the following to use it for go routine management:
• Config entry Replication
• ACL replication - tokens, policies, roles and legacy tokens
• ACL legacy token upgrade
• ACL token reaping
• Intention Replication
• Secondary CA Roots Watching
• CA Root Pruning
Also added the StopAll call into the Server Shutdown method to ensure all leader routines get killed off when shutting down.
This should be mostly unnecessary as `revokeLeadership` should manually stop each one but just in case we really want these to go away (eventually).
