Small Biography Clean up tasks

[alliyya]

• [ ] culturalForm.py: LN 456: create_cf_map() - Add exception handling for when file cannot be opened
• [ ] event.py: LN 88: format_date() - Log dates that are BC and determine how to format them
• [ ] utilities.py LN 333: get_reg() - Deprecate this function (remove function and usage, get_value() or tag.get("REG") would be better to use)
• [ ] utilities.py LN 316: create_cwrc_uri() - Deprecate this function (Remove function and update its usage to be create_uri("cwrc", term))
• [ ] Add additional exception handling for when files are being read (There are a few in utilities and other files, see task 1)
• [x] context_mapping.csv - update predicates/context uris as needed
• [x] intertextuality.py - update predicates/context uris as needed
• [ ] testcase.json Add testcase ids for intertextuality (influence/intertextuality/response)

[alliyya]

Just a heads up @kobbard I've updated predicates/uris for the most part since I needed those updates for data updates and hadn't seen any commits from you. Apologies if I've duplicated your efforts inadvertently.