Support customizing node selectors / taints / tolerations to default catalog pods

Story: As an OpenShift administrator I want to apply node selectors and taints / tolerations to cluster default catalog pods so that I can keep worker nodes free workloads that are considered cluster infrastructure.

Background: currently the OperatorHub API allows to enable / disable the cluster-wide default catalogs. While the controller for this API runs on the control plan the pods that get created run on worker nodes. There is currently no way to effectively move these pods to infrastructure nodes (nodes with a particular label) because the namespace is managed by CVO and the CatalogSource / pod spec is managed by the marketplace operator. Thus, they are poised to take up resources from paid worker nodes.

Acceptance criteria:

• admin can supply custom node selectors and taints / tolerations to the pods created by the default set of catalogs
• pods associated to default OLM catalog can be moved to a different nodes