use a category label to group things

[jstrachan]

see https://github.com/hawtio/hawtio-kubernetes/issues/68 for more details but we will often use labels to group things into areas.

it'd be nice to use a street/city kind of layout and using labels to group things. e.g. the first main label values could group things into villages; then make a street and put all the RCs on that street.

e.g. using just 1 label we could have N streets for each value of the label.

If there is a 2nd label which sub-groups a street, we could have sub-streets. e.g. "communication" street could have 2 roads coming off it for "front end" and "back end" apps?

I guess we might want "logical town" and "physical town" where in physical town you'd have a street per host ;)