Resolve "Improvement of tests"

Closes #32 (closed)

Not done due to time:

• test cases for inherited attributes, non-terminal opts, and for endpoints, that always apply
• Investigate possibility of parallelizing tests

changed milestone to %1.0.0

added Component: Backend Component: Configuration labels

assigned to @rschoene

enabled an automatic merge when the pipeline for 42a01614 succeeds

merged

mentioned in commit fe5bffe0