Facilitate use of built-in images outside of OCK

[zabdulre]

In certain cases, a user may attempt to use a image that is built into OCK without an OCK system. In these cases, the user may have to pull the required built-in image manually and tag the image properly in order to use it. Furthermore, the user is not currently able to use the catalog mirror and copy commands to save the image to their custom registry because built-in images are not output by the catalog mirror command.

In order to facilitate the use of built-in images, we need to account for the case where a user attempts to use a image that is built into OCK without an OCK system. Here are two ideas:

1. Use the "# extra-image:" label in the catalog to include built-in images in the catalog mirror command output. This will allow the user to easily move the image to a private registry.

2. Add container-registry.oracle.com as a registry on all OCK nodes even if the user specifies a custom registry. And make all built-in images use partially-qualified names (i.e. olcne/ock instead of container-registry.oracle.com/olcne/ock). This ensures that images are pulled from the container-registry if they are not available in the user's custom registry. This also ensures that built-in images are used if available on the node.

[George-Aeillo]

I think we should go the route of the extra-image label, I think that would be clearer and could avoid potential confusion where different images could be in the public registry versus a private registry.