feature: podLabels and podAnnotations

[veezhang]

• podLabels
• podAnnotations
• helm&doc

[veezhang]

For examples:

helm install nc ./charts/nebula-cluster --namespace=default \
  --set 'nameOverride'='nc' \
  --set 'nebula.storageClassName'=standard \
  --set 'nebula.podLabels.A='A \
  --set 'nebula.podLabels.app\.kubernetes\.io/component='NoExists \
  --set 'nebula.podAnnotations.A='A \
  --set 'nebula.podAnnotations.nebula-graph\.io/cm-hash='NoExists

kubectl get pod -l app.kubernetes.io/cluster=nc \
  -o custom-columns='NAME:.metadata.name,LabelsA:.metadata.labels.A,Component:.metadata.labels.app\.kubernetes\.io/component,AnnotationsA:.metadata.annotations.A,CMHash:.metadata.annotations.nebula-graph\.io/cm-hash'
NAME            LabelsA   Component   AnnotationsA   CMHash
nc-graphd-0     A         graphd      A              94ea457be88fae25
nc-graphd-1     A         graphd      A              94ea457be88fae25
nc-metad-0      A         metad       A              ff6a3a99d3b3fc58
nc-metad-1      A         metad       A              ff6a3a99d3b3fc58
nc-metad-2      A         metad       A              ff6a3a99d3b3fc58
nc-storaged-0   A         storaged    A              563a13ee319762c8
nc-storaged-1   A         storaged    A              563a13ee319762c8
nc-storaged-2   A         storaged    A              563a13ee319762c8

[MegaByte875]

This is a utility function, move it to pkg/util/maputil more better, what do you think?

[veezhang]

In the future, it may come out separately to create a golang mod or repo, so consider making him less dependent.
Or we will provide a golang pkg in the future that does not depend on Nebula Operator?
Or as you said, move it to pkg/util/maputil ?
What do you think?

[MegaByte875]

We need make a plan to refactor this part, you can commit another pr to complete it.