Port free flow tests to new staggered
Tests should be ported one by one in separate merge requests. In principle, the new implementations are available in !2201. Move changes from problem_new.hh
and main_new.hh
to problem.hh
, main.hh
and properties.hh
. Be careful as !2201 is already partly outdated. !2830 (merged) is a port based on the current master.