MM-13606 Remove consumeAndClose and clean up integration response handling (#10066)

* MM-13606 Remove consumeAndClose

* Allow overriding HTTPService's request timeout

* MM-13606 Clean up integration response handling

* Properly close httptest servers

* Address feedback

* Only call buf.Bytes when necessary

* Properly check for errors in doOutgoingWebhookRequest

* Add comment explaining ignored ioutil.ReadAll errors

app/notification_push.go

@@ -286,10 +286,9 @@ func (a *App) sendToPushProxy(msg model.PushNotification, session *model.Session
 		return
 	}
 
+	defer resp.Body.Close()
+
 	pushResponse := model.PushResponseFromJson(resp.Body)
-	if resp.Body != nil {
-		consumeAndClose(resp)
-	}
 
 	if pushResponse[model.PUSH_STATUS] == model.PUSH_STATUS_REMOVE {
 		mlog.Info(fmt.Sprintf("Device was reported as removed for UserId=%v SessionId=%v removing push for this session", session.UserId, session.Id), mlog.String("user_id", session.UserId))