Add load balancer charts to Omnibus Grafana dashboard
We introduced NGINX VTS based metrics to Omnibus, but we don't have them in our Grafana dashboard yet.
We should add charts similar to what we do for GitLab.com for HA Proxy:
- Throughput
- Latency
- Error Rate
We could also include additional detail, if we can, on whether it's a backend or frontend request, etc.