Add the possibility to configure PodDisruptionBudget of Nuxeo nodes

Pod Disruption Budgets (PDBs) allow workloads to be configured to limit the number of it’s replicas that are permitted to be down at the same time. When things like automated maintenance evict pods and shuffle things around, PDBs help ensure that all the replicas are not evicted at the same time, ensuring that at least some minimum number is running at all times to avoid possible service disruptions.