Canary Deployment for Network PreFlight Checks

**What would you like to be added**:
As an EKS Anywhere administrator deploying to virtualized environments such as VMWare, CloudStack, and potentially Nutanix, I would like a preflight check that tests for DHCP and internet access.

**Why is this needed**:
Currently, the only indication that DHCP is missing is error messages about the cluster timing out on creation. Deep troubleshooting is required to learn that DHCP is misconfigured, or not enabled at all.

Given that the only way to test DHCP, and to validate the network itself (which may not be the same vlan the administration machine was booted in) is to deploy something into it. One solution may be to deploy a very small vm "canary" that can be checked for ip address success, and provide an API endpoint that simply responds "OK" if the canary can reach an internet endpoint such as checkip.amazonaws.com.

No files, tests, or entry points are named. Start by reviewing the existing EKS Anywhere preflight checks and cluster provisioning path, then determine how a canary could validate DHCP and internet access in VMware, CloudStack, or Nutanix environments; done means the check reports actionable success or failure before cluster creation.

Written by the indexing model from the issue text.