Add boot_and_list_server benchmark

Added boot_and_list_server benchmark.
Config example is below.

{
    "NovaServers.boot_and_list_server": [
        {
            "args": {
                "flavor_id": 1,
                "image_id": "ccc8fe37-9289-437b-a88c-fc4678656c75"
            },
            "runner": {
                "type": "continuous",
                "times": 1,
                "active_users": 1
            },
            "context": {
                "users": {
                    "tenants": 1,
                    "users_per_tenant": 1
                }
            }
        }
    ]
}

Change-Id: I55f9125612a68c9168db686972f52c702ec5803f