Show metadata for a specific subscription

Example:

\b
    $ wva subscriptions show speed
    {'buffer': 'queue', 'interval': 5, 'uri': 'vehicle/data/VehicleSpeed'}

def show(ctx, short_name):
    """Show metadata for a specific subscription

Example:

\b
    $ wva subscriptions show speed
    {'buffer': 'queue', 'interval': 5, 'uri': 'vehicle/data/VehicleSpeed'}
"""
    wva = get_wva(ctx)
    subscription = wva.get_subscription(short_name)
    cli_pprint(subscription.get_metadata())