Do not accept -c or --config option for the worker subcommand

[mikhail-sakhnov]

while we don't use config in the worker process we still accept it as a cli argument which makes CLI interface confusing

[kke]

There's some other flags returned with the GetPersistentFlagSet that are not needed where it is used. Also, it is used in "intermediary" sub-commands such as k0s token, which by itself does nothing and should not have any flags apart from --help.

[kke]

Then what about the etcd mid-command? There's some storage-type checking code in the k0s etcd but as far as I can tell, it will never execute (changing storage type to sqlite and doing k0s etcd leave does not seem to complain about storage type, maybe it does on otherwise working config with a running cluster, not sure)

[jnummelin]

Should be fixed with #1247

[trawler]

fixed with #1389