Add controller.extraServices list

[hedgieinsocks]

This PR suggests adding controller.extraServices key of list type for declaring additional controller services.

This will make it possible for us to declare two controller services for MetalLB like this:

controller:
  service:
    annotations:
      metallb.universe.tf/loadBalancerIPs: 1.2.3.10
  extraServices:
    - annotations:
        metallb.universe.tf/loadBalancerIPs: 1.2.3.11

And get the following result:

apiVersion: v1
kind: Service
metadata:
  annotations:
    metallb.universe.tf/loadBalancerIPs: 1.2.3.10
  labels:
    helm.sh/chart: haproxy-ingress-0.15.0-alpha.3
    app.kubernetes.io/name: haproxy-ingress
    app.kubernetes.io/instance: haproxy-ingress
    app.kubernetes.io/version: "v0.15.0-alpha.3"
    app.kubernetes.io/managed-by: Helm
  name: haproxy-ingress
  namespace: default
spec:
  externalTrafficPolicy: "Local"
  ports:
    - name: "http-80"
      port: 80
      protocol: TCP
      targetPort: http
    - name: "https-443"
      port: 443
      protocol: TCP
      targetPort: https
  selector:
    app.kubernetes.io/name: haproxy-ingress
    app.kubernetes.io/instance: haproxy-ingress
  type: "LoadBalancer"
---
kind: Service
metadata:
  annotations:
    metallb.universe.tf/loadBalancerIPs: 1.2.3.11
  labels:
    helm.sh/chart: haproxy-ingress-0.15.0-alpha.3
    app.kubernetes.io/name: haproxy-ingress
    app.kubernetes.io/instance: haproxy-ingress
    app.kubernetes.io/version: "v0.15.0-alpha.3"
    app.kubernetes.io/managed-by: Helm
  name: haproxy-ingress-extra-0
  namespace: default
spec:
  externalTrafficPolicy: "Local"
  ports:
    - name: "http-80"
      port: 80
      protocol: TCP
      targetPort: http
    - name: "https-443"
      port: 443
      protocol: TCP
      targetPort: https
  selector:
    app.kubernetes.io/name: haproxy-ingress
    app.kubernetes.io/instance: haproxy-ingress
  type: "LoadBalancer"