[client] Remove endpoint address on peer disconnect, retain status for activity recording (#4228)

* When a peer disconnects, remove the endpoint address to avoid sending traffic to a non-existent address, but retain the status for the activity recorder.

client/internal/peer/iface.go

@@ -18,4 +18,5 @@ type WGIface interface {
 	GetStats() (map[string]configurer.WGStats, error)
 	GetProxy() wgproxy.Proxy
 	Address() wgaddr.Address
+	RemoveEndpointAddress(key string) error
 }