AC-1707 Add support for optional annotations to headless and pod services

[joshbench]

This PR will allow users to add custom annotations to the headless and pod services created by AKO.

The specific functionality we are looking for is to use external-dns to create DNS records that map to these pod addresses, and we need to add annotations to these services to do so.

These annotations can be added by adding the following to the AerospikeCluster spec:

  seedsFinderServices:
    headless:
      annotations:
        foo: bar
    pod:
      annotations:
        foo: bar

And validated by checking the generated services:

• pod:

  ❯ kubectl describe service aerospike-0-0 -n aerospike
  Name:                     aerospike-0-0
  Namespace:                aerospike
  Labels:                   <none>
  Annotations:              foo: bar
  Selector:                 statefulset.kubernetes.io/pod-name=aerospike-0-0
  Type:                     NodePort
  

• headless:

  ❯ kubectl describe service aerospike -n aerospike
  Name:                     aerospike
  Namespace:                aerospike
  Labels:                   aerospike.com/cr=aerospike
                            app=aerospike-cluster
  Annotations:              foo: bar
                            service.alpha.kubernetes.io/tolerate-unready-endpoints: true
  Selector:                 aerospike.com/cr=aerospike,app=aerospike-cluster
  Type:                     ClusterIP
  

I have tested this by creating AerospikeClusters, both specifying these annotations and excluding them.