health: Implementing arity host selection
health: Implementing arity host selection

When selecting nodes to perform the benchmark, we shall group the VMs
modulo arity.

This patch is grouping the selected VMs per Hypervisors and per arity
and save the computed groups for later analysis.

enovance/edeploy,lebauce/edeploy,lebauce/edeploy,redhat-cip/edeploy,enovance/edeploy,redhat-cip/edeploy,lebauce/edeploy,lebauce/edeploy,enovance/edeploy,redhat-cip/edeploy,redhat-cip/edeploy,enovance/edeploy