Display image creation date

[anmazzotti]

Starting from elemental-operator 1.7.2, the ManagedOSVersion will have a new metadata created timestamp.
This is in Unix time format. For example:

apiVersion: elemental.cattle.io/v1beta1
kind: ManagedOSVersion
metadata:
  name: baremetal-v2.2.0-3.9-os
  namespace: fleet-default
spec:
  metadata:
    created: 1732636343
    displayName: SL Micro Baremetal 6.1 OS
    platforms:
      - linux/x86_64
      - linux/aarch64
    upgradeImage: registry.suse.com/suse/sl-micro/6.1/baremetal-os-container:2.2.0-3.9
  type: container
  version: v2.2.0-3.9

It would be nice if we can somehow display this timestamp in a human readable format when listing the ManagedOSVersions.
Would also be nice to do a conversion based on the browser's timezone. In any case I think it should be best to explicitly display the used timezone.

[aalves08]

@anmazzotti when will operator 1.7.2 be published?