Make it easier to re-run on failure #5
Description
The program may fail after already having successfully uploaded some citations to Thoth. Attempting to re-run the failed command will then fail again due to the program attempting to upload "duplicates" of the existing citations.
Might only be an issue when running via docker/obp-loader, as this performs citation extractions for each chapter as a separate subprocess, i.e. some subprocesses may complete successfully before another fails and cancels the main process.