Option control for CNI installation.

This is part of the external control plane story, documented here (see last update): https://issues.redhat.com/projects/MAISTRA/issues/MAISTRA-2488

As per the recent agreements, we manage the control-plane and data-plane cluster components with different operator instances, to avoid a single operator talk to multiple K8S APIs. That is, on the control-plane side we only install discovery chart, meaning we do not need i.e. any CNI plugin installation on that cluster.

Right now the CNI installation is unconditionally happens on SMCP operations regardless of any static/dinamic configuration. The plan is to add a new annotation to the operator deployment to control this behavior.