This also includes a change to the workflow used in the test-case.
There are quite complex reasons for this, as explained here:
https://github.com/elsa-workflows/elsa-core/issues/728#issuecomment-794319236
The real crux of it is that the workflow must have an activity
which suspends it, and that activity that suspends the workflow
must not be the starting activity. This is why I added an unused
set-variable activity as the starter.
This commit shows that the various persistence test cases _mostly_
work OK, with the one exception of ActivityExecuted.
32bcf9a751