Individual Drush command to export GraphQL schema

On dev branch, if you wanted to review.

What if "--server" is not an option? I think it should be an argument.

function x(array $server_ids, array $options = [...])
drush my-command --type='json' 'my_server_id_01' 'my_server_id_02'

Or Drush have a native support for comma separated values. I handles it as CSV.
function x(string $server_ids, array $options = [...])
drush my-command --type='json' 'my_server_id_01,my_server_id_02'

Fine to move server to arg, I’ll just make it an optional arg. Default to all servers.