Ability to define Application Icon in Topology View

1. Proposed title of this feature request
   Custom Icon's in Topology View
2. What is the nature and description of the request?
   Today you can only change the icon of a application if you adjust the app.openshift.io/runtime (and pick from a small list of runtimes: https://github.com/openshift/console/blob/master/frontend/public/components/catalog/catalog-item-icon.tsx)

To help developers better visualize there applications we should allow them to set a app.openshift.io/runtime-icon label (as well) allowing them to specify a URI to a svg file that better represents their application. 

1. Why does the customer need this? (List the business requirements here)
   This is a nice to have (but isn't necessary) 

1. List any affected packages or components.
   Console