Mechanism to restart pods running outdated proxies

[hercynium]

Recently I was looking for better ways to manage our Istio upgrades at work, and a real pain point was identifying and restarting all the deployments that were still connected to the old Istio revision after we deployed a new revision and updated the webhook tags.

The sail operator looks really exciting, but it doesn't (yet) have this feature #74 ... so I decided to try creating it. I'm a beginner at golang, but here's what I came up with: https://github.com/hercynium/istio-fortsa

It's very much a work-in-progress, but feel free to use it for ideas to add this functionality to Sail. Even if it's not useful to the project, I'm always welcome to input on how to make my code better, too - issues, comments, PRs, etc!