oaiharvester: refextract task fix

* Checks properly if the PDF is downloaded successfully inside the
  refextract task.

Reviewed-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>
template: fix for unicode url handling

Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
formatter: addition of format.mime_type column

* Adds upgrade for the `Format` table by adding `mime_type`.

Signed-off-by: Konstantinos Kostis <konstantinos.kostis@cern.ch>
jsonalchemy: validation fixes

Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
uploader: typos fixes

Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
records: better PID list

Signed-off-by: Esteban J. G. Gabancho <esteban.gabancho@gmail.com>
uploader: files to link addition

* Adds new option for linking files with record via custom FFL MARC
  field.

* Adds `legacy` step to uploader insert worflow for filling-up "bibxxx"
  tables.  (addresses #1772)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
previewer: addition of support for Documents

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>