deposit: checkbox support addition

* Saves the checkbox values on changed.

* Corrects FileUploadField RequiredIf validation.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
Co-authored-by: Javier Martin Montull <javier.martin.montull@cern.ch>
Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>