Audit log formatter (might be ready for review)

On its own it's ready for review.  I've tested this by arbitrarily setting `audit_log=True` on the `succeeds_with` logging and hit an endpoint, and saw two logs emitted, not in much detail.

Emitting 2 logs instead of 1 so that less filtering on the endpoint has to happen, and also just in case the combined log is too big.

I'd like to actually finish one of the logging rest request issues and run it with this formatter though before merging it.