Add option to disable Helm chart repository in the cluster

As reported in RFE-1388, there is a need to remove default Red Hat Helm chart repo from the cluster. Removing HelmChartRepository instance does not work, because the default configurations is delivered within OpenShift payload, and such resources are monitored by Cluster Version Operator - in case of a resource removal, it gets recreated, and there is no way around it, at least not the one that should be applied in the production.

Thus, we should make possible to disable a given Helm chart repository. A new disabled field on HelmChartRepository CRD, will signal to the Helm endpoints that such repo should not be used. Status of that field, and/or its modification can be used by other cluster components (e.g. console UI) for disabling/enabling some functionalities.