Optimization Tests and Experiments

[stefan-grafberger]

Description

All of the optimizations work for all the mlinspect example pipelines, but more extensive testing needs to be done. But we need to do optimization experiments anyway, so now that we do the optimization experiments, we can use the experiment code also to build some unit tests.

[stefan-grafberger]

~Maybe it would also be nicer to move the optimizations subpackage outside of the execution subpackage.~

[stefan-grafberger]

We need to add support for several new operations, most importantly, the DummyClassifier to have a very cheap baseline classifier.