Avoid using resource status for reconcile logic

[ankitathomas]

Using a ClusterCatalog object's status for the catalogd controller's reconcile logic is an anti-pattern we should avoid.

We currently read from ClusterCatalog status to determine whether a catalog is ready to be polled again (examples:

catalogd/internal/controllers/core/clustercatalog_controller.go

Line 246 in a0037dd

if catalog.Spec.Source.Image.Ref != catalog.Status.ResolvedSource.Image.Ref {

,

catalogd/internal/controllers/core/clustercatalog_controller.go

Lines 254 to 255 in a0037dd

	nextPoll := catalog.Status.ResolvedSource.Image.LastPollAttempt.Add(catalog.Spec.Source.Image.PollInterval.Duration)
	if nextPoll.After(time.Now()) && catalog.Generation == catalog.Status.ObservedGeneration {

)

The status field should ideally be treated as a write-only field by the controller - we should update the controller so it can track information about a ClusterCatalog's current state without having to reference the ClusterCatalog's status field.

Follow up based on #384 (comment)

See https://book.kubebuilder.io/reference/good-practices, https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api-conventions.md#spec-and-status