Add logs integration to istio charms

[ca-scribner]

Enhancement Proposal

Enhancement Proposal

We need to connect all logs provided by istio to the cos stack. In this task we should investigate what components of Istio emit logs, and for any core components integrate them into the cos stack. Any logs for other parts of Istio (the waypoint or ingress gateways) should be handled in other issue

Dod:

• Investigate what logs are provided by istio
  • For any logs that come from waypoint or ingress gateways (or other non-core parts of istio), create new issues on those repos to capture those logs
• Integrate the logs from istio's core to the cos stack