Collect nginx controller metrics in prometheus

[Voxelot]

Enable nginx metrics and collect them in prometheus. This may require changes to the nginx installation script.

https://docs.nginx.com/nginx-ingress-controller/logging-and-monitoring/prometheus/

[rfuelsh]

• for fuel-deployment-v2: https://github.com/FuelLabs/fuel-deployment-v2/pull/43

deployed and working in new fuel dev cluster

replicating to current DEV & PROD clusters

[rfuelsh]

replicated to DEV & PROD - got nginx metrics