Add lightweight ephemeral VMs "execution_wrapper" or "docker" interface

[jerrymarino]

I'm using rules_ios and buildfarm to build and run tests at scale. Currently, there is a rule in rules_ios ios_vm_test to run VMs. I'd like to adpot this to fit into the exectuion_wrapper paradigm: bazelbuild/bazel-buildfarm#439

The possibilities to pull this in the original PR were to 1. make it the VM runner rule ( done ) 2. make it a "docker" interface ( waiting on virtio block device changes to virtualization framework in ventura ) or 3. make it an execution wrapper to do the "scp" of bits. This is blocked until the file system works good and the tart issue is addressed