add metrics for subscribe with RebalanceListener1

[nikitapecasa]

This is a follow-up task to #122.
Most probably we need to add similar metrics as for subscribe with RebalanceListener

def subscribe(topics: Nes[Topic], listener: Option[RebalanceListener[F]]) = {
  val listener1 = listener.map(rebalanceListener)
  for {
    _ <- count("subscribe", topics.toList)
    r <- self.subscribe(topics, listener1)
  } yield r
}

skafka/skafka/src/main/scala/com/evolutiongaming/skafka/consumer/Consumer.scala

Line 639 in b76b257

def subscribe(topics: Nes[Topic], listener: Option[RebalanceListener[F]]) = {