Add --list-queues option to sidekiq-cluster

The --dryrun option shows the full command sidekiq-cluster will run. This new option just lists the matched queues (mostly useful in conjunction with --queue-selector), one per line.

$ bin/sidekiq-cluster --list-queues --queue-selector 'resource_boundary!=cpu&urgency=high'
authorized_keys
authorized_project_update:authorized_project_update_project_recalculate
authorized_projects
email_receiver
gitlab_shell
incident_management_pending_escalations_alert_check
incident_management_pending_escalations_alert_create
merge
merge_requests_delete_source_branch
merge_requests_handle_assignees_change
merge_requests_resolve_todos
merge_requests_sync_code_owner_approval_rules
pipeline_cache:expire_job_cache
pipeline_default:pipeline_metrics
pipeline_hooks:build_hooks
pipeline_processing:build_success
pipeline_processing:ci_initial_pipeline_process
pipeline_processing:pipeline_process
pipeline_processing:stage_update
process_commit
project_cache
prometheus_create_default_alerts
update_highest_role