Remove monitoring ports from the service definition for webservice

Summary

As a follow-up to !1726 (comment 478533921) we should decide our next steps for service monitoring. Currently we define ports on the Service as described here https://github.com/prometheus-operator/prometheus-operator/blob/master/Documentation/user-guides/getting-started.md .

for service.type=LoadBalancer this will add the following ports to the internal LB:

port	target
8080	puma
8181	workhorse
8083	puma.monitoring.exporter
9229	workhorse.monitoring.exporter

The downside of this approach is that all of these ports will be available on a loadbalancer if one is defined. We discussed in the linked issue either creating a dedicated service for these monitoring ports, or removing them in favor of pod monitors.

One thing to keep in mind is backwards compatibility to anyone that is using servicemonitors with prometheus-operator though it's not clear if this would be a big impact.