MB-38921: Add backup service audit module
MB-38921: Add backup service audit module

Change-Id: Ic9639be9dc52a57168456c3c0891d24565b348c1
Reviewed-on: http://review.couchbase.org/c/kv_engine/+/126493
Tested-by: Carlos Gonzalez <36e622408f153c22cbe9b942c093fb5a1daab1e3@couchbase.com>
Reviewed-by: Daniel Owen <b3fc0e1a51f252986e60be7da121b74d3ac6845f@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine