Werk #12696: Let the core helpers time out

With Checkmk 2.0 we have splitted the Microcore Checkmk helper processes into Fetcher and Checker helpers. Since this split, the service check timeout of the "Check_MK" and "Check_MK Discovery" services (as configured via setup) was not applied to the whole check execution pipeline.

The timeout was applied to the fetcher execution before, which is normally taking most of the time. But there are also cases where the execution of the checker takes too long, reaching the configured timeout.

With this change we now apply the service check timeout to the whole pipeline, including the processing in the checker helpers._

To the list of all Werks