[MM-64244] Add websocket disconnect reason metric (#31032)

We've recently spent some effort improving websocket reconnection logic. With this commit, I've augmented the websocket reconnect metric to include a disconnect reason. This will help us measure the impact of these changes in production.

server/einterfaces/metrics.go

@@ -48,7 +48,7 @@ type MetricsInterface interface {
 	DecrementWebSocketBroadcastBufferSize(hub string, amount float64)
 	IncrementWebSocketBroadcastUsersRegistered(hub string, amount float64)
 	DecrementWebSocketBroadcastUsersRegistered(hub string, amount float64)
-	IncrementWebsocketReconnectEvent(eventType string)
+	IncrementWebsocketReconnectEventWithDisconnectErrCode(eventType string, disconnectErrCode string)
 
 	IncrementHTTPWebSockets(originClient string)
 	DecrementHTTPWebSockets(originClient string)