introduce different service types for session-server

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What does this MR do?

This MR adds possibility to change Service type of session-server.

Why was this MR needed?

Currently, there is no way to configure session-server without LoadBalancer. But some cases, we don't want to add a new load balancer just for session server. We can use ClusterIP or NodePort service type to expose session server.

What's the best way to test this MR?

For ClusterIP, values can be like this:

sessionServer:
  enabled: true
  internalPort: 8093
  externalPort: 9000
  service:
    type: ClusterIP

Advertise address: $session-service-name.$namespace.svc.cluster.local:9000

For Headless:

sessionServer:
  enabled: true
  internalPort: 8093
  externalPort: 9000
  service:
    type: Headless

Advertise address: $pod_ip:9000

For NodePort:

sessionServer:
  enabled: true
  internalPort: 8093
  externalPort: 9000
  nodePort: 30093
  service:
    type: NodePort

Advertise address: $node_ip:30093

You can also use auto assigned nodePorts.

sessionServer:
  enabled: true
  internalPort: 8093
  externalPort: 9000
  service:
    type: NodePort

Advertise address: $node_ip:$auto_assigned_port

Note: If publicIP is defined then it will use publicIP as a host regardless of the service type.

What are the relevant issue numbers?

#533