knowledge: fix get_kbr_values returned value

* Fixes the returned value of get_kbr_values:
  list of one element list instead of list of elements.

Signed-off-by: Leonardo Rossi <leonardo.r@cern.ch>
indexer: PEP8/257 improvements in models

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
records: PEP8/257 improvements in models

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
editor: PEP8/257 improvements in models

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
accounts: enhancement in UserUsergroup

* Adds in the model the update of the date after last change of
  user status.

Signed-off-by: Leonardo Rossi <leonardo.r@cern.ch>
restful: addition of validate method

* Adds a `validate` method in RestfulPagination class that checks
  the ranges of `page` and `per_page` parameters.

Signed-off-by: Konstantinos Kostis <konstantinos.kostis@cern.ch>
uploader: workflow definition refactor

* Refactors the "insert" workflow definitions to conform with
  the standard pattern of workflows. This will also avoid the current
  issue that the workflows registry has the "insert" workflow with key
  None.

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