Implement switching to metrics-server

Following points to consider to implement for switching to metrics-server:

• Add this feature in Tech-Preview mode
• Config option to switch metrics-server: https://issues.redhat.com/browse/MON-3214
  • enable-metrics-server by switching to TechPreviewNoUpgrade mode
• Flow of creating/deleting objects:
  • Deploy metrics-server
  • Verify metrics-server resource metrics api is working
  • Update APIService object to point to metrics-server
  • Delete prometheus-adapter resources
• Deploy in HA mode (2 replicas which is the case for all components we deploy)

Acceptance Criteria:

• we have a PR in the CMO repo
• we have a POC
• people can start deploying it in their cluster