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/security_update_check.go

@@ -81,8 +81,9 @@ func (s *Server) DoSecurityUpdateCheck() {
 					return
 				}
 
+				defer res.Body.Close()
+
 				bulletins := model.SecurityBulletinsFromJson(res.Body)
-				consumeAndClose(res)
 
 				for _, bulletin := range bulletins {
 					if bulletin.AppliesToVersion == model.CurrentVersion {