=clu #16224 Add test for cluster node restart
Merge pull request #16266 from akka/wip-16224-cluster-restart-test-patriknw

=clu #16224 Add test for cluster node restart
+ akka-cluster-metrics: new akka module
* new akka module split from akka-cluster
* provide sigar provisioning
* fix ewma usage
* resolve #16121
* see #16354
make strategy private