expose basic connection stats via Conn.ConnectionStats (#5281)

* Add ConnectionStats

* remove for loop

* Add comments

* Update comments

---------

Co-authored-by: Marco Munizaga <git@marcopolo.io>

internal/utils/connstats.go

@@ -0,0 +1,14 @@
+package utils
+
+import "sync/atomic"
+
+// ConnectionStats stores stats for the connection. See the public
+// ConnectionStats struct in connection.go for more information
+type ConnectionStats struct {
+	BytesSent       atomic.Uint64
+	PacketsSent     atomic.Uint64
+	BytesReceived   atomic.Uint64
+	PacketsReceived atomic.Uint64
+	BytesLost       atomic.Uint64
+	PacketsLost     atomic.Uint64
+}