[EKS] [request]: Enable Worker Orchestration in separate VPC to Cluster

**Tell us about your request**
Currently it does not seem possibly to orchestrate workers in different VPCs to the EKS control plane.

**Which service(s) is this request for?**
EKS

**Tell us about the problem you're trying to solve. What are you trying to do, and why is it hard?**
We currently isolate development environments in separate VPCs, and are looking to adopt EKS. The cleanest pattern for us would be to stand up one EKS cluster that can embed workers into each of the development environment VPCs.

**Are you currently working around this issue?**
Currently we would have to stand up separate EKS clusters per environment.

Start by reviewing the EKS worker-orchestration and VPC requirements described in this issue, including the current separate-cluster workaround. Done means establishing whether one EKS cluster can place workers in multiple development VPCs and documenting the supported approach or remaining limitation.

Written by the indexing model from the issue text.