workflows: Holding Pen stabilization

* Adds search feature through tags.

* Simplifies the sort code server side.

* Gets request parameters before application ones.

* Adds data extraction methods.

* Changes the way we are creating object to removes
  cyclic dependencies.

Signed-off-by: Guillaume Lastecoueres <guillaume.lastecoueres@cern.ch>
workflows: Holding Pen object history

* Adds the history of an object on the details page.

Signed-off-by: Guillaume Lastecoueres <guillaume.lastecoueres@cern.ch>
workflows: merging corrections

* Fixes import format.

* Fixes tests presentation.

* Fixes unit tests.

* Fixes PEP257.

* Fixes useless utf-8 conversion.

* Fixes _task_result type modification.

* Fixes python3 compatibility.

* Reformats the javascript code.

Signed-off-by: Guillaume Lastecoueres <guillaume.lastecoueres@cern.ch>
workflows: test cleanup

* Makes sure that all objects are cleaned up after running
  tests.

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

* Removes specific tasks created for the INSPIRE site.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
workflows: better widget and filtering

* Changes the way we do the filtering.

* Reduces number of requests.

* Fixes workflows problem with persistent data.

* Fixes approval widget.

Signed-off-by: Guillaume Lastecoueres <guillaume.lastecoueres@cern.ch>
workflows: bug fix and Holding Pen ergonomy

* Fixes a bug about the creation date of snapshot.

* Fixes not taking snapshot when continue a workflow.

* Fixes the order in the history.

* Removes details column.

* Adds details when clicking on the title.

* Hides search field of the datatable.

* Add a mapping to convert Object version to their correct
  printable text.

Signed-off-by: Guillaume Lastecoueres <guillaume.lastecoueres@cern.ch>
workflows: missing RQ worker code

* Adds missing RQ worker code for .get() and .status()

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