Fix ServiceController test

[danmoseley]

Fix #57115

This outer loop test has apparently never passed as it was written backwards: it was intended to test that if you have a service A depending on (requiring) service B, then a call serviceControllerForB.Stop(stopDependentServices: false)) will throw IOE. Instead it was stopping service A, which of course works fine.

The confusion was likely because the word dependency is overloaded in that it can mean both depended-on and depending-on. When we created a test service XYZ that depends on another test service, we named the latter XYZ.Dependency (ie XYZ ---> XYZ.Dependency). On the Win32 SCM API, services you depend on are named "dependencies". Nevertheless in everyday English, "dependency" is often used to mean the reverse -- "the thing depending on another". On ServiceController, the API is clearer: DependentServices are those that depend on YOU, and ServicesDependedOn are those you depend on; the method Stop(bool stopDependentServices) has a boolean to first stop services that depend on you (to which you are a prerequisite).

Renamed the test service that's depended on to be XYZ.Prerequisite.
Fixed test to attempt to stop that instead.
Added more of the handy off-by-default tracing in the tests.

Note these tests only run in Windows+OuterLoop+Elevated, which may be one reason it wasn't noticed.

[ViktorHofer]

LGTM. Thanks for making this clear.