workflows: object navigation

* Adds buttons for going to previous/next workflow object
  in the Holding Pen detailed display. The previous/next
  functionality is based from the state of the maintable
  order.

Tested-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
workflows: previous/next amendment

* Moves the previous/next buttons to the nav bar on
  Holding Pen detailed display.

* Factors out some code to separate functions.

* Removes unused workflows.css.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
workflows: initial upgrade

* Adds initial upgrade from Invenio v1.x. for workflows module.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>