Unify structured logging for common operator

[Jeffwan]

All of below have reference in different operators. This makes logs very messy and we need to consolidate to one common utility

1. "github.com/sirupsen/logrus"
2. "github.com/go-logr/logr" - default logger interface used by reconciler generated by kubebuilder.
3. "sigs.k8s.io/controller-runtime/pkg/log" - implementation of "go-logr/logr"
4. https://github.com/kubeflow/common/blob/master/pkg/util/logger.go - use logrus underneath
5. "k8s.io/klog"

[PatrickXYS]

Do we have any preference in those log libraries? @Jeffwan

[Jeffwan]

@PatrickXYS We do prefer json logging. No big preference. The challenge is different components use different solutions

• kubebuilder
• logrus

Let's see if we can consolidate into one