add a "concurrent databases" or "number of databases" counter to pgbench summary document

[acalhounRH]

add a "concurrent databases" or "number of databases" counter to pgbench summary document? I am trying to iterate over a set tests using the add1 feature for # of DBs. The problem is associating the X number of DBs on grafana. the way we are currently indexing the results we are just indicating which DB the summary results are associated to and includes nothing about the number of DBs currently under test for that iteration. the table at the link below should show 3 sets of test with 1, 2 , and 3 data bases, unfortunately there isn't any field I can use to identify and group to accomplish the desired result so it just shows a single set with a unique count of DBs at 3.

http://marquez.perf.lab.eng.rdu2.redhat.com:3000/d/5ni0mp0Zz/aws-pgbench-summary-with-rook-ceph?orgId=1&from=1572545911231&to=1572551015024&var-user=acalhoun&var-clustername=acalhoun-10-31-2019-3db-test&var-UUID=e9db825c-14ad-534d-b237-15a99ea27e94&var-interval=10s&var-datasource=Prometheus%20-%20Public%20cloud&var-net_device=All&var-block_device=All&var-instances=All

@aakarshg @dustinblack