Add support for 'Dualstack without public IPv4' for 'ip-address-type'

[Richard-de-Vries]

AWS recently introduced the ability to forgo public ipv4 adresses on internet facing Application Loadbalancers

Adding support for this would result in a significant costs savings on a lot of users that can make use of this feature.

I'm willing to make a PR to add support for this, if this feature is wanted in the project.

[Richard-de-Vries]

I just saw that the functionality has already been added