Test KadaiEngine with different ConnectionManagementModes

[bruderj15]

Following #44 and the discussion in #491 (comment), revisit the old Taskana-Tests, transfer those worth to Kadai and extend where necessary.

[bruderj15]

The related PR: Taskana/taskana#1383

[bruderj15]

Seems like they tested the modes for each Service-Implementation separately:

• EXPLICIT
  • ClassificationServiceImpl
  • TaskServiceImpl
  • WorkbasketServiceImpl
• AUTOCOMMIT
  • ClassificationServiceImpl
  • TaskServiceImpl
  • WorkbasketServiceImpl
• PARTICIPATE
  • Doesn't seem to be tested at all

I think we can do better.
Possibly by using @TestTemplate with some clever Provider-Logic.

[bruderj15]

Possibly by using @TestTemplate with some clever Provider-Logic.

No. That's overkill and doesn't hit the point.

Easiest approach: Take functionality of UserServiceImpl and test with all the different ConnectionManagementModes.
Most isolated approach: Create or leverage (I think I've seen one before) a Test-Mapper and test the modes with it.

Take second if feasible.

EDIT: Yes, such a mapper exists already: TaskTestMapper