enabling rest api config perf tests for jenkinst usage

enabling rest api config perf tests for jenkinst usage

this commit depends on https://git.opendaylight.org/gerrit/#/c/18333/
and together with this gerrit it implements
https://trello.com/c/nHYXeOYa/94-performance-prepare-e2e-flow-push-test-using-jan-s-scripts

how it should work can be seen in sandbox
https://jenkins.opendaylight.org/sandbox/job/openflowplugin-csit-1node-cds-config-performance-only-master/

Change-Id: Ib731fbbe2092d93ee65d2a6ecff36372ed6610cc
Signed-off-by: Peter Gubka <pgubka@cisco.com>