Invalid detection of response status in `executeRequestAndUpdateMetrics`

[Tomasz-Smelcerz-SAP]

There are some problems in executeRequestAndUpdateMetrics function (pkg/event/skr_events_listener.go)

1. The response code detection is invalid. request.Response is NOT related to the HttpServer response: It is valid for a Response received from remote server when using HTTP Client to send a request.
2. The metrics.RecordHTTPInflightRequests increase/decrease seems to be wrongly placed. It should "wrap" the call to next.ServeHTTP(), but it does not.

[Tomasz-Smelcerz-SAP]

One idea to detect status code correctly is to use CapturingResponseWriter - a ResponseWriter capable of recording the status code.
See: #592 (comment)