port instance_usage_audit_log tests into nova v3 part2

this ports the instance_usage_audit_log tests and corresponding
client into v3. In v3 api, There is no the url:
GET /os-instance-usage-audit-log/:(id).
but the filter:before will be used instead in index action.

Partially implements blueprint nova-v3-api-tests

Change-Id: I726a27bc4f374d3bae98a903196bf2265c31e67c
Merge "port instance_usage_audit_log tests into nova v3 part2"