[python][pmflow] Improve style, add some, use wrapper helpers

4 jobs for !2681 with feature/python-main-file in 7 minutes and 33 seconds (queued for 9 seconds)
Child pipeline (parent) detached
Status Name Job ID Coverage
  Linting
passed python linting #24121

00:00:23

 
  Configure
passed select tests #24122

00:03:52

 
  Build
passed build dumux #24123

00:02:43

 
  Test
passed test dumux #24124

00:00:34