render_list function does not handle external IPs due to boto3 api error

[andysnowden]

If you are trying to use the lamda with non-vpc IP address the AWS api/boto3 will fail with the following error

[ERROR]	2022-11-19T18:50:05.007Z	75a3e5b4-4302-4493-9824-539647241114	The Availability Zone is required for IP address '172.25.18.11' because it is not in the VPC

To resolve you need to specify the AZ in the render_list function. This should prob be added as an option param in the formation template

def render_list(ip_list):
    """
    Render a list of targets for registration/deregistration
    """
    target_list = []
    for ip in ip_list:
        target = {
            'Id': ip,
            'AvailabilityZone': 'all'
        }
        target_list.append(target)
    return target_list