client: Refactory client-state and client-info

- Merge client-state with client-info and provide separate
calls for each separate subnode.
- Handle config related items under meta object.
- Disable stats by default with compilation flag
- Handle persistent under control
schema: Rename CLIENT_STATE_NAME TO FSM_STATE_NAME
testing: Adapt wickedd_mon.sh to client-state handling
fsm: Add ni_ifworker_control_set_persistent|usercontrol
client-state: Allow save/load of incomplete structure