Fix misleading errors with synthetic service

[shashankram]

Bug description:
When client pods are not associated with a k8s service, the controller currently creates synthetic services. Some parts of the controller code report misleading errors when they cannot find k8s information for the synthetic service.

{"level":"error","component":"kube-provider","time":"2021-02-16T19:54:56Z","file":"client.go:123","message":"[Kubernetes] Error fetching Kubernetes Endpoints from cache"}
{"level":"error","component":"envoy/lds","error":"Error fetching port:protocol mapping for service client-one/client-one.client-one.osm.synthetic-084dcde9-9d6a-4511-8a77-cd7bb5b8c3ae","time":"2021-02-16T19:54:56Z","file":"inmesh.go:39","message":"Error retrieving port to protocol mapping for service client-one/client-one.client-one.osm.synthetic-084dcde9-9d6a-4511-8a77-cd7bb5b8c3ae"}

These errors are misleading and must be fixed.

Synthetic services will be removed with #2064.

[shashankram]

Synthetic service has been removed by PR #2619 for issue #2064.