Add connection-lifetime metric

Signed-off-by: nscavell <nick.scavelli@gmail.com>
More metrics
 - Number of timers
 - Size of event loop and worker pool
 - Cluster host/ip guage

Signed-off-by: nscavell <nick.scavelli@gmail.com>
Use the actual port for the server metric name (i.e. wildcard port)

Signed-off-by: nscavell <nick.scavelli@gmail.com>