general: importing modules from packages fix

* Uses Flask-Registry for importing modules from packages.

Signed-off-by: Eirini Psallida <eirini.psallida@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
sqlalchemy: custom EncryptedType removal

* Removes the custom EncryptedType and uses implementation from
  SQLAlchemy-Utils.  (closes #2343)

Signed-off-by: Konstantinos Kostis <konstantinos.kostis@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
demosite: PendingDeprecationWarning on populate

* NOTE adds PendingDeprecationWarning for demosite populate command.
  (addresses #2394)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
workflows: admin dropdown menu fix

* Fixes covering of admin dropdown menu in hp_maintable template.
  (closes #2384)

Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
workflows: log output in Holding Pen

* Adds display of the log for BibWorkflowObject's in the Holding
  Pen detailed view.

Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>