Integrated Pipeline: refactored CalculationParsingFlow tests, added stream assertion for normal completion

Integrated Pipeline: FileParsingTaskEndTree emitted by TreeParserFlow now includes the number of generated parsing tasks

-improved error messages given by findFirstMatchingStreamElement

Integrated Pipeline: element search assertion now takes matchers that work on a subset of the element stream only

-elements with non-compliant classes are automatically considered matching failures
-simplifies property matcher structure

Integrated Pipeline: improved readability of graph stage tests, more functionality for ArchiveUnpackingFlow