added byoip support for load balancer and nat-gateway#1873

DO-rrao merged 4 commits into

digitalocean:maindigitalocean/doctl:mainfrom

rbhatia-code:rbhatia/LBAAS-4168-byoip-lb-nat-gatewayrbhatia-code/doctl:rbhatia/LBAAS-4168-byoip-lb-nat-gatewayCopy head branch name to clipboard