In Custom Resources view the Resource Age column is not formatted properly

[danielpacak]

What steps did you take and what happened:

1. Define a CR and create an instance of it. For example:

   $ kubectl apply -f https://github.com/aquasecurity/starboard/blob/master/kube/crd/vulnerabilityreports-crd.yaml
   $ kubectl apply -f https://github.com/aquasecurity/starboard/blob/master/kube/examples/vulnerabilities.yaml
   

2. Navigate to the CR instance in Octant UI
   
3. As you can see the Resource Age column is not formatted as date. What's more even if the CR defines Age as additional printer column the CR views renders the redundant Resource Age column

What did you expect to happen:

1. If a CRD does not define Age as additional printer column then format Resource Age column as date. BTW, I'd probably rename Resource Age to Age to be consistent with kubectl output
2. If a CRD defines Age as additional printer column then format Age column as date and do not display Resource Age column.

Anything else you would like to add:

N/A

Environment:

• Octant version (use octant version): 0.16.0
• Kubernetes version (use kubectl version): 0.19.1
• OS (macOS 10.15, Windows 10, Ubuntu 19.10 etc): macOS 10.15

[lenriquez]

@wwitzel3 if you don't mind I can take this one