AWS: Add support for load balancer source ranges
AWS: Add support for load balancer source ranges

This refactors #21431 to pull a lot of the code into cloudprovider so it
can be reused by AWS.

It also changes the name of the annotation to be non-GCE specific:
service.beta.kubernetes.io/load-balancer-source-ranges

Fix #21651

kubernetes/cloud-provider-openstack,kubernetes/cloud-provider-openstack,kubernetes/cloud-provider-openstack