The new --orchestrator flag is showing up on too many commands

[dhiltgen]

With the recent refinement of the docker stack command to include kubernetes support, it seems we've wired up the --orchestrator flag too broadly. It is now showing up on top-level commands that it should not.

For example:

% docker container cp --help

Usage:	docker container cp [OPTIONS] CONTAINER:SRC_PATH DEST_PATH|-
	docker cp [OPTIONS] SRC_PATH|- CONTAINER:DEST_PATH

Copy files/folders between a container and the local filesystem

Use '-' as the source to read a tar archive from stdin
and extract it to a directory destination in a container.
Use '-' as the destination to stream a tar archive of a
container source to stdout.

Options:
  -a, --archive               Archive mode (copy all uid/gid information)
  -L, --follow-link           Always follow symbol link in SRC_PATH
      --orchestrator string   Orchestrator to use (swarm|kubernetes|all)

and

% docker volume --help      

Usage:	docker volume COMMAND

Manage volumes

Options:
      --orchestrator string   Orchestrator to use (swarm|kubernetes|all)

Commands:
  create      Create a volume
  inspect     Display detailed information on one or more volumes
  ls          List volumes
  prune       Remove all unused local volumes
  rm          Remove one or more volumes

Run 'docker volume COMMAND --help' for more information on a command.

I believe this flag should only show up on the stack command for now.