Create extension with ctr binary

[rothgar]

We currently remove ctr from the default containerd build so users won't rely on the binary for managing containers on the host.

Some workloads require the binary for various host level scanning. We should probably keep the binary off of the base OS, but we should also enable users who need it to use it.

If we create an extension it will be built and tracked with talos builds and should remain compatible. Are there any other common container runtime tools needed for 3rd party software we should consider adding to an optional extension?