Remove several pieces of audit-related code
Summary: Ref T10978. This code (mostly related to the old ADD_AUDIT transaction and some to the "store English text in the database" audit reasons) is no longer reachable.
Grepped for removed symbols:
- getActionNameMap (unrelated callsites exist)
- getActionName (unrelated callsites exist)
Also audited some commits.
Reviewed By: chad
Maniphest Tasks: T10978
Differential Revision: https://secure.phabricator.com/D17267