Add support to AWS clusterpool to support a list of zones

[chrisahl]

hive allows you to pass in a set of zones for the region that you want to run vms on. However, right now on cm cli for AWS, this data is not passed on to hive. This results in all zones in the region being used and for each region, a NAT gateway is created. When we are doing dev/test and don't need High Availability, we can reduce the number of regions used and this will reduce the number of AWS NAT Gateways used. This results in much less cost for each cluster. In the case of a SNO cluster, we can reduce to just using one region in the zone. So in us-east-1, we will go from defining 5 NAT gateways to 1. This should significantly reduce AWS cost.

[chrisahl]

@chrisahl is working on this

[chrisahl]

@itdove Can you assign this to me? UI dos not allow me to. Thanks.