ingress/model: Add GetPort function for BackendPort
ingress/model: Add GetPort function for BackendPort

Simple utility function for getting string representation of backend
port.

Signed-off-by: Tam Mach <2524536bcff1dac29d2f6b38b02eb7c94efb5019@cilium.io>

cilium/cilium,cilium/cilium,cilium/cilium,cilium/cilium,cilium/cilium