chore: add status code for request_total metrics (#5188)

weed/stats/http_status_recorder.go

@@ -0,0 +1,21 @@
+package stats
+
+import "net/http"
+
+type StatusRecorder struct {
+	http.ResponseWriter
+	Status int
+}
+
+func NewStatusResponseWriter(w http.ResponseWriter) *StatusRecorder {
+	return &StatusRecorder{w, http.StatusOK}
+}
+
+func (r *StatusRecorder) WriteHeader(status int) {
+	r.Status = status
+	r.ResponseWriter.WriteHeader(status)
+}
+
+func (r *StatusRecorder) Flush() {
+	r.ResponseWriter.(http.Flusher).Flush()
+}