[OPENENGSB-3606] added function to load a model from a specific timestamp to the EngineeringDatabaseService
[OPENENGSB-3606] adapted the EDBConverter to load the correct version of sub models. Adapted test setups.
[OPENENGSB-3606] added integration test for testing the correct behaviour
Merge pull request #832 from Arcticwolf/OPENENGSB-3606

[OPENENGSB-3606] load submodels in correct version