Frontend Health Check Behaviour

[c-kruse]

I do not think that frontend /api/health it is doing what it was written to do. It appears to return 200 pretty much regardless of what happens with the backend call: https://github.com/skupperproject/skupper-example-hello-world/blob/590abaa875e7c2ea68e05bb21879ed8e509ebe18/frontend/python/main.py#L110-L114

It could be useful for this to return non-okay when the backend service is unavailable for automated test scenarios where we could hook it up to pod readiness or just have a cleaner endpoint to poll.