Migrate Cloudstack provider to use new cluster controller

**What would you like to be added**:
I would like to move the eks-a controller logic for cloudstack away from the legacy controller and to use the new broken-out cluster controller instead

**Why is this needed**:
This code is on a deprecation path and I would like to use the newer code path to make sure it is properly tested and maintained

The issue names the CloudStack EKS-A logic, the legacy controller, and the new broken-out cluster controller, but no files or tests. Start by locating both controller paths and comparing their CloudStack responsibilities. Done means the CloudStack provider uses the new controller path, the deprecated path is no longer used for this logic, and the behavior is covered by appropriate tests.

Written by the indexing model from the issue text.