Update dot output visuality

[shireenf-ibm]

• add node also for real peers which are not connected. implementation idea: by adding a new member peers list to the connlist analyzer so we can iterate it for dot graph and find peers that don't have a node yet

example test: (check it on branch new_exposure_analysis_first_branch)

$ ./bin/k8snetpolicy list --dirpath tests/test_egress_exposure_with_named_port -o dot
digraph {
}

Instead, output should include:

digraph {
        subgraph "cluster_hello_world" {
                color="black"
                fontcolor="black"
                "hello-world/workload-a[Deployment]" [label="workload-a[Deployment]" color="blue" fontcolor="blue"]
                label="hello-world"
        }
}