add workspace cleanup on HF release jobs

So far the cleanups were added to the nightly jobs which consumed much space every day.

1. This could also be done on the 7/8/9 jobs for the ondemand testing jobs (except the first one that builds the product because of later task to perform).
   For instance the chain beginning with:
   https://qa2.nuxeo.org/jenkins/view/Depl/job/Deploy/job/IT-release-on-demand-build-nx810/
2. The same applies for the HF package building chain where the job building the HF should not be cleaned up but the other ones should in case of success.
   For instance the chain beginning with:
   https://qa2.nuxeo.org/jenkins/view/Private/job/Private/job/HFBuilding/job/IT-HF-PKG-build-nx810/