Currently, we only ever add to the list of resources for the cluster. We never remove items. This causes problems when switching between clusters with different sets of resources. We should make sure the resource list is accurate for the current cluster whenever we run API discovery, which means we need to be able to remove resources from the list when they're not present on the current clusters. Arguably this is a general bug since console doesn't update correctly when a CRD is removed even without multi-cluster.