Fix tests that expect to receive VM Service events

[derekxu16]

We must pass onDone and onError arguments when listening to service event streams in tests, otherwise those tests will pass silently when the testee crashes.

See the changes to pkg/dds/test/cpu_sample_streaming_test.dart in https://dart-review.googlesource.com/c/sdk/+/426300 for an example.

[mraleph]

See the changes to pkg/dds/test/cpu_sample_streaming_test.dart in https://dart-review.googlesource.com/c/sdk/+/426300 for an example.

I have undone this change because it revealed another bug (#60672) and did another change instead: added a helper withServiceConnection which listens for VmService.onDone and makes sure that it is only called after we call dispose. I think more tests should adopt this helper as well.

I think there is also another/additional safety net we could consider putting in: wrap spawn of testee process into additional safety net which checks that the process exited successfully and not crashed. But I am leaving this for now.

Though we should certainly also fix #60672 and add closing of event streams back.