BibDocFile: escape file URLs in /files tab

Co-authored by: Jerome Caffaro <jerome.caffaro@cern.ch>
Signed-off-by: Ludmila Marian <ludmila.marian@gmail.com>
Merge pull request #11 from ludmilamarian/master-bibdocfile-escape-files-urls

BibDocFile: escape file URLs in /files tab