Make affinity/antiaffinity topologyKey and required/preferred parameters configurable for podDistribution setting

Hello,

We would like to have replicas spread across availability zones. Currently, the podDistribution settings only work with the hostname topologyKey as far as I can tell:
https://github.com/Altinity/clickhouse-operator/blob/master/pkg/model/affinity.go#L504
https://github.com/Altinity/clickhouse-operator/blob/master/pkg/model/affinity.go#L529
https://github.com/Altinity/clickhouse-operator/blob/master/pkg/model/affinity.go#L561

The only way we have found to have pods spread across zones now is to use one pod template per zone which is repetitive and error-prone.

I also noticed that pod affinity is currently enforced using PreferredDuringSchedulingIgnoredDuringExecution and pod anti affinity using RequiredDuringSchedulingIgnoredDuringExecution. Can we also make this configurable?

2 additional optional settings like this could work:

podDistribution:
- type: ReplicaAntiAffinity
  topologyKey: kubernetes.io/zone
  affType: preferredDuringSchedulingIgnoredDuringExecution

Thanks

Start in pkg/model/affinity.go at the referenced podDistribution handling and trace how its settings are represented and applied. Check the existing configuration and validation paths before defining the supported topologyKey and affinity-type values. Done means replica affinity and anti-affinity can target a configured topology and use the requested required or preferred mode.