Update resize scripts to use an image OCID from a config file.

[andriy-safe-ai]

We would like to be able to change the image that is used when a node is added to the cluster using the resize scripts. Over time, we will make modifications to our image such as upgrading the NVIDIA drivers and we would like for new nodes to be deployed with the updated image instead of having to manually upgrade software like we have to do with existing compute nodes.