Prososition - new metric that display last time we queried for Cost data. #152
Description
I was wondering if there is a metric that indicates when the exporter last queried for cost data. When we have configured the component to cache cost data and query every 12 hours, the time of day when we receive an update on the cost drifts by a few seconds each time.
If we have this info, we can display "this is the cost until timestamp".