Return a list of the images that are on the provider

    CLI Example:

    .. code-block:: bash

        salt-cloud --list-images my-proxmox-config

def avail_images(call=None, location='local'):
    '''
    Return a list of the images that are on the provider

    CLI Example:

    .. code-block:: bash

        salt-cloud --list-images my-proxmox-config
    '''
    if call == 'action':
        raise SaltCloudSystemExit(
            'The avail_images function must be called with '
            '-f or --function, or with the --list-images option'
        )

    ret = {}
    for host_name, host_details in six.iteritems(avail_locations()):
        for item in query('get', 'nodes/{0}/storage/{1}/content'.format(host_name, location)):
            ret[item['volid']] = item
    return ret