workflows: Holding Pen change

* Adds new bibclassify workflow task for faster execution, taking
  only parts of the document.

* Saves the BibWorkflowObject after removing the action.

FIXME: Add signoff when DONE.
workflows: improve error messages

* Properly sets error messages upon unexpected errors during
  workflow execution.

* Integrates the error messages into the Holding Pen detailed
  view of an object.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
workflows: change to panel style
workflows: actions changes and details fixes

Co-authored-by: Guillaume Lastecoueres <PX9e@gmx.fr>