R1:adf209e6555a

When registering a device, write a device ID

Summary:
Ref T5833. In some cases, we need to know if an Almanac device is the localhost or not, so we can either handle or forward the request.

To accomplish this, write a device ID when running `bin/almanac register`.

Using `--allow-key-reuse` and `--identify-as`, multiple devices are permitted to //authenticate// as one device but //identify// as different devices. In the Phacility cluster, this allows all the `repoXXX` machines to have one keypair (making…