Update console operator for single-node clusters

https://github.com/openshift/enhancements/pull/555
https://github.com/openshift/api/pull/827

The console operator will need to support single-node clusters.

We have a console deployment and downloads deployment. Each will to be updated so that there's only a single replica when high availability mode is disabled in the Infrastructure config. We should also remove the anti-affinity rule in the console deployment that tries to spread console pods across nodes.

The downloads deployment is currently a static manifest. That likely needs to be created by the console operator instead going forward.

Acceptance Criteria:

• Console operator deploys console with 1 replica and no anti-affinity rules when not in high availability mode
• Console operator deploys the downloads deployment with 1 replica when not in high availability mode
• The console and downloads deployments do not change when in high availability mode
• The feature is well-covered by tests