Sail Operator supports injecting infrastructure configuration on Gateway Class.

Given an Openshift topology we can set an HPA for this infrastructure class with proper replica number, providing, at least at this moment an initial HA for deployed Istio Pilot containers and also dataplane containers.

• If the infrastructure topology is "SingleReplica", set minimum to 1.
• Otherwise, set minimum to 2.
• In any case, set maximum to 10.

Pending: the port for downstream sail-operator patch of https://github.com/istio-ecosystem/sail-operator/pull/1465/files