Support ServiceMonitor creation for Appsody operator

[navidsh]

Support creation of ServiceMonitor object for Appsody operator's metric service.

Things to consider:

• way to disable ServiceMonitor objects creation
• way to changing metrics service port?
• authentication?
• supporting https for the port?

[arturdzm]

Also need to know which Prometheus server to feed data to (label selector)

[navidsh]

From Artur:

Possibly can enable JWT security using this ServiceAccount token /var/run/secrets/kubernetes.io/serviceaccount/token