add nodeAntiaffinities

[arminfelder]

all cockroach nodes should run with "preferredDuringSchedulingIgnoredDuringExecution"

e.g.

...
 affinity:
    podAntiAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 1
        preference:
          matchExpressions:
          - key: another-node-label-key
            operator: In
            values:
            - another-node-label-value

[chrislovecnm]

You can add this affinity rule in the CR if you like.

[chrislovecnm]

This is missing in the API currently. @udnay found the issue.