workflows: INSPIRE approval action fix

* Amends inspires_approval action to save its outcome
  to the extra_data of the object so workflows using
  this action will be able to branch their execution
  paths depending on the outcome of the action.

* Adds task halt_to_render in order to stop the workflows
  execution render and the completed submission template
  before before long tasks start so the user wont have to wait.

Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
deposit: literature workflow fix

* Amends literature workflow to take different
  execution paths depending on the inspires_approval
  outcome.

Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
deposit: add new submission (with no approval)
workflows: several updates

* Finalize the literature workflow that interacts with robotupload
  and the Holding Pen.

* Fix missing encoding in some files.

* Add receivers.py file for handling signals from the workflows
  module.

Co-authored-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>