* Extend --dry-run to support string values for dry run strategies
'client', 'server', and 'none'
* Ensure --dry-run is set and accessed via cmdutil
* Deprecate --dry-run (unset), --dry-run=true, and --dry-run=false
Kubernetes-commit: af52beda260257e81cc9e19e9e5108b682ee93d6