[POPPyCore] Run an "finally-like" task whatever the pipeline ends (nominally or after exception)
It should be useful to have the possibility to run a "final" task whatever happens in the pipeline (exception raised or nominal end)
Use case:
- A temporary output directory is created at the beginning of the pipeline execution
- In all case (succeeded/failed processing, exception raised) this directory must be moved in another place before ending pipeline execution