Why these changes are being introduced:
* Update Aardvark class to use current field method conventions for the remaining fields

How this addresses that need:
* Add field methods and associated private methods for format, identifiers, languages, links, locations, notes, provider, publishers, rights, subjects, and summary
* Refactor get_links and get_source_link method to avoid error if links field is None
* Update unit tests with current conventions

Side effects of this change:
* None

Relevant ticket(s):
* https://mitlibraries.atlassian.net/browse/TIMX-285

* Create submethods for get_rights
* Rename get_dates submethods for consistency

* Refactor get_source_link method
* Update dependencies to address new safety vulnerability
* Updates to address linting errors
* Add XMLTransformer.record_is_deleted unit test