hubble ui: add traffic direction as column

[Tim-herbie]

Cilium Feature Proposal

Is your feature request related to a problem?

No, but it simplify network troubleshooting within the Kubernetes Cluster

Describe the feature you'd like

Currently it is not possible to choose "traffic direction" as column in the hubble ui. When I click on one line, I can see the traffic direction, but troubleshooting would be faster when I could see this information without selecting a line.