Add missing dll tests

[ronald-jaepel]

The dll interface tests had two conditions that were not checked correctly:

1. The dll test was supposed to compare the dll interface to the cli interface, which was never actually called. One commit fixes that and now throws an error.
2. The dll test did not check for simulations with only one component. One commit adds a single-component case by modifying the simulation to only include one component. Now we get dimensionality errors.