Koha::UI::Form::Builder::Biblio
Helper to build a form to add or edit a new biblio
    my $form = Koha::UI::Form::Builder::Biblio->new(
        {
            biblionumber => $biblionumber,
        }
    );
Generate subfield's info for given tag, subfieldtag, etc.
Return list of authorized values for given tag, subfield
Create unique key for subfields