Require a license for full KBART output, fall back to work_id for KBART title ID if no DOI available

[brendan-oconnell]

Proquest ExLibris cannot use the Thoth KBART output without the title_id field being exported, which is currently an issue for works with no DOI, since Thoth uses DOI as title_id. Fall back to using Thoth work_id for KBART title ID if no DOI available.