Add support for Istio ingress route

[MichaelThamm]

Enhancement Proposal

In addition to Traefik's ingress, we also need Istio ingress for service mesh support. Keep in mind that we also support Traefik ingress and we need to handle conditionally switching between the two.

We need to decide (product decision), when multiple ingresses are connected, how to handle these scenario:

1. limit: 1 on both traefik_route and istio_ingress
2. Have logic to handle the which ingress to prioritize when both related
   • e.g. Blocked status and recommend which one to use
   • e.g. Keep the first ingress (before second relation) as the actual ingress and set Blocked warning that second ingress is not active

This will be important to implement before we implement service mesh in COS starting 26.10

[simskij]

If both are added, block and use neither of them. Do not advice the user on which to use, only tell them that they need to pick one.