[FEATURE] Add maskedFields to OpensearchRole

[cgroschupp]

To support field masking it is necessary to add maskedFields to the indexPermissions within the OpensearchRole resource.

Example OpensearchRole:

apiVersion: opensearch.opster.io/v1
kind: OpensearchRole
metadata:
  name: mask
spec:
  opensearchCluster:
    name: test
  name: mask
  indexPermissions:
    - indexPatterns:
        - "*"
      allowedActions:
        - "read"
      maskedFields:
        - "message"

[salyh]

This would absolutely make sense. Thank you for your contribution.