Fixed bugs in the `polish` module related to BioCyc annotations and Nones
- Adjusted handling of BioCyc identifiers within the
polish_annotations
function of the modulepolish
- Added requirement for importlib_resources=5.13.0 to Pipfile
- Added code to cope with missing sub-database prefixes for BioCyc identifiers
- Changed NaN identifier handling
- Fixed issue with None prefix identifier pairs being listed in invalid_curies.tsv