Support containerd pulling from custom registries

Description

As a OpenShift customer, I want the containerd on Windows nodes to be configurable so that it can pull images from user's registries.

This is necessary to support disconnected environments as users need to pull the k8s pause image and any images required for their workloads from on-prem, air-gapped registries.

Engineering Details

On the Linux side, to allow CRI-O to pull from mirrored registries, MCO looks at ImageDigestMirrorSets and ImageTagMirrorSets in the cluster and consolidates them down into a registries.conf file (placed in the MachineConfigs) that is placed on each node.

WMCO will have to do something similar for containerd - WMCO should look at the IDMS/ITMS and, on each Windows node, create hosts.toml files, one for each desired registry.

We will also have to change config_path in containerd config file to point to the directory holding the newly created hosts.toml(s)

Acceptance Criteria

• containerd configuration is updated based on the mirrors defined in IDMS/ITMS
• images can be successfully pulled from the mirror registries without manual intervention