Multi themes bug fix
Multi themes bug fix

allow user to select multiple themes when adding or editing guidance

cau-vfu/DMPonline_v4,BibNumUMontreal/DMPonline_v4,BibNumUMontreal/DMPonline_v4,BibNumUMontreal/DMPonline_v4,DigitalCurationCentre/DMPonline_v4,DigitalCurationCentre/DMPonline_v4,cau-vfu/DMPonline_v4,DigitalCurationCentre/DMPonline_v4,cau-vfu/DMPonline_v4