Better support for analysis with specific ingress controllers

[adisos]

The problem : assume workload foo has an Ingress/Route rule, and a tight network policy that only permits ingress access to foo from a certain namespace/pod of a specific ingress-controller.
Currently the analysis does not identify specific ingress-controller, thus assumes the required connection from Ingres/Route rules is blocked by network policies. (Only if the ingress access is open to any in-cluster workload, it identifies permitted access from a general ingress-controller to the workload).

This can be refined.
Consider specific known labels of namespaces for ingress-controllers.
Consider new input parameter to specify such labels to be considered in the analysis.

[adisos]

initial enhancement: identify ingress-nginx by labels/namespace
and also openshifft ingress controller