Axonframework: Timestamp of scheduled events incorrect in Test Fixtures

[abuijze]

When scheduling an event in the test fixtures, the timestamp of the event is set to the current system time, instead of the simulated time in the fixture.

[smcvb]

Back ported this solution to branch 3.4.x, to be a part of release 3.4.2.

[przemyslawboszczyk]

@abuijze @smcvb Thanks a lot for taking care of it. Makes code much cleaner for saga testing! Appreciate it!