global: enable Flask-IIIF extension
- NEW Uses Flask-IIIF extension providing various image manipulation capabilities.
- NEW Adds possibility to refer to documents and legacy BibDocFiles via special path such as /api/multimedia/image/recid:{recid} or /api/multimedia/image/recid:{recid}-{filename} or /api/multimedia/image/uuid with proper permission checking. (closes #3080) (closes #3084)
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Signed-off-by: Harris Tzovanakis <me@drjova.com>