Fixes #5938: Make services management compatible with Windows - branch 3...

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I just spent ages trying to understand this comment, without success. After reading the whole technique, I figured it out. But to avoid me and anyone else having to do that again in the future, could you please replace it by something like this comment:

On Windows, we can't use processes: promises to detect the current status, so we just call the service_{start,stop} bundles to ensure service state