Rewrite stdout/err redirection logic in ANCM

The StandardStreamRedirection logic in ANCM uses `CancelSynchronousIo` to kick the redirection thread out of its blocking `ReadFile` call and waits a hardcoded 2 seconds to allow the thread to exit before it calls `TerminateThread` on the thread. This works reasonably well in the vast majority of cases (most of the time, the 2 seconds is enough), but occasionally, we have to resort to the `TerminateThread` and in a small number of _those_ cases, the thread might be doing something dangerous like holding the OS loader lock.

This is how we end up with issues like https://github.com/dotnet/aspnetcore/issues/45066.

#49942 improved upon this situation by making the timeout configurable (so the thread can have more than 2 seconds to exit), but it would be cleaner to eliminate `TerminateThread` usage here entirely.